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Carretero-Guillén A, Treviño M, Gómez-Climent MÁ, Dogbevia GK, Bertocchi I, Sprengel R, Larkum ME, Vlachos A, Gruart A, Delgado-García JM, Hasan MT. Dentate gyrus is needed for memory retrieval. Mol Psychiatry 2024:10.1038/s41380-024-02546-0. [PMID: 38609585 DOI: 10.1038/s41380-024-02546-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/03/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024]
Abstract
The hippocampus is crucial for acquiring and retrieving episodic and contextual memories. In previous studies, the inactivation of dentate gyrus (DG) neurons by chemogenetic- and optogenetic-mediated hyperpolarization led to opposing conclusions about DG's role in memory retrieval. One study used Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-mediated clozapine N-oxide (CNO)-induced hyperpolarization and reported that the previously formed memory was erased, thus concluding that denate gyrus is needed for memory maintenance. The other study used optogenetic with halorhodopsin induced hyperpolarization and reported and dentate gyrus is needed for memory retrieval. We hypothesized that this apparent discrepancy could be due to the length of hyperpolarization in previous studies; minutes by optogenetics and several hours by DREADD/CNO. Since hyperpolarization interferes with anterograde and retrograde neuronal signaling, it is possible that the memory engram in the dentate gyrus and the entorhinal to hippocampus trisynaptic circuit was erased by long-term, but not with short-term hyperpolarization. We developed and applied an advanced chemogenetic technology to selectively silence synaptic output by blocking neurotransmitter release without hyperpolarizing DG neurons to explore this apparent discrepancy. We performed in vivo electrophysiology during trace eyeblink in a rabbit model of associative learning. Our work shows that the DG output is required for memory retrieval. Based on previous and recent findings, we propose that the actively functional anterograde and retrograde neuronal signaling is necessary to preserve synaptic memory engrams along the entorhinal cortex to the hippocampal trisynaptic circuit.
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Affiliation(s)
- Alejandro Carretero-Guillén
- Division of Neuroscience, University Pablo de Olavide, Seville, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Mario Treviño
- Max Planck Institute for Medical Research, Heidelberg, Germany
- Instituto de Neurociencias, Universidad de Guadalajara, Guadalajara, 44130, México
| | | | - Godwin K Dogbevia
- Max Planck Institute for Medical Research, Heidelberg, Germany
- Health Canada, Ottawa, ON, Canada
| | - Ilaria Bertocchi
- Max Planck Institute for Medical Research, Heidelberg, Germany
- Neuroscience Institute Cavalieri-Ottolenghi (NICO), University of Turin, Turin, Italy
| | - Rolf Sprengel
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | | | | | - Agnès Gruart
- Division of Neuroscience, University Pablo de Olavide, Seville, Spain
| | | | - Mazahir T Hasan
- Achucarro Basque Center for Neuroscience, Leioa, Spain.
- Max Planck Institute for Medical Research, Heidelberg, Germany.
- NeuroCure, Charité - Universitätsmedizin, Berlin, Germany.
- Ikerbasque - Basque Foundation for Science, Bilbao, Spain.
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Galanis C, Neuhaus L, Hananeia N, Turi Z, Jedlicka P, Vlachos A. Axon morphology and intrinsic cellular properties determine repetitive transcranial magnetic stimulation threshold for plasticity. Front Cell Neurosci 2024; 18:1374555. [PMID: 38638302 PMCID: PMC11025360 DOI: 10.3389/fncel.2024.1374555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 03/13/2024] [Indexed: 04/20/2024] Open
Abstract
Introduction Repetitive transcranial magnetic stimulation (rTMS) is a widely used therapeutic tool in neurology and psychiatry, but its cellular and molecular mechanisms are not fully understood. Standardizing stimulus parameters, specifically electric field strength, is crucial in experimental and clinical settings. It enables meaningful comparisons across studies and facilitates the translation of findings into clinical practice. However, the impact of biophysical properties inherent to the stimulated neurons and networks on the outcome of rTMS protocols remains not well understood. Consequently, achieving standardization of biological effects across different brain regions and subjects poses a significant challenge. Methods This study compared the effects of 10 Hz repetitive magnetic stimulation (rMS) in entorhino-hippocampal tissue cultures from mice and rats, providing insights into the impact of the same stimulation protocol on similar neuronal networks under standardized conditions. Results We observed the previously described plastic changes in excitatory and inhibitory synaptic strength of CA1 pyramidal neurons in both mouse and rat tissue cultures, but a higher stimulation intensity was required for the induction of rMS-induced synaptic plasticity in rat tissue cultures. Through systematic comparison of neuronal structural and functional properties and computational modeling, we found that morphological parameters of CA1 pyramidal neurons alone are insufficient to explain the observed differences between the groups. Although morphologies of mouse and rat CA1 neurons showed no significant differences, simulations confirmed that axon morphologies significantly influence individual cell activation thresholds. Notably, differences in intrinsic cellular properties were sufficient to account for the 10% higher intensity required for the induction of synaptic plasticity in the rat tissue cultures. Conclusion These findings demonstrate the critical importance of axon morphology and intrinsic cellular properties in predicting the plasticity effects of rTMS, carrying valuable implications for the development of computer models aimed at predicting and standardizing the biological effects of rTMS.
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Affiliation(s)
- Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lena Neuhaus
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nicholas Hananeia
- 3R-Zentrum Gießen, Justus-Liebig-Universitat Giessen, Giessen, Germany
| | - Zsolt Turi
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter Jedlicka
- 3R-Zentrum Gießen, Justus-Liebig-Universitat Giessen, Giessen, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Virtuoso A, Galanis C, Lenz M, Papa M, Vlachos A. Regional Microglial Response in Entorhino-Hippocampal Slice Cultures to Schaffer Collateral Lesion and Metalloproteinases Modulation. Int J Mol Sci 2024; 25:2346. [PMID: 38397023 PMCID: PMC10889226 DOI: 10.3390/ijms25042346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/08/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Microglia and astrocytes are essential in sustaining physiological networks in the central nervous system, with their ability to remodel the extracellular matrix, being pivotal for synapse plasticity. Recent findings have challenged the traditional view of homogenous glial populations in the brain, uncovering morphological, functional, and molecular heterogeneity among glial cells. This diversity has significant implications for both physiological and pathological brain states. In the present study, we mechanically induced a Schaffer collateral lesion (SCL) in mouse entorhino-hippocampal slice cultures to investigate glial behavior, i.e., microglia and astrocytes, under metalloproteinases (MMPs) modulation in the lesioned area, CA3, and the denervated region, CA1. We observed distinct response patterns in the microglia and astrocytes 3 days after the lesion. Notably, GFAP-expressing astrocytes showed no immediate changes post-SCL. Microglia responses varied depending on their anatomical location, underscoring the complexity of the hippocampal neuroglial network post-injury. The MMPs inhibitor GM6001 did not affect microglial reactions in CA3, while increasing the number of Iba1-expressing cells in CA1, leading to a withdrawal of their primary branches. These findings highlight the importance of understanding glial regionalization following neural injury and MMPs modulation and pave the way for further research into glia-targeted therapeutic strategies for neurodegenerative disorders.
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Affiliation(s)
- Assunta Virtuoso
- Neuronal Morphology Networks and Systems Biology Laboratory, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
- Hannover Medical School, Institute of Neuroanatomy and Cell Biology, 30625 Hannover, Germany
| | - Michele Papa
- Neuronal Morphology Networks and Systems Biology Laboratory, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Center BrainLinks–BrainTools, University of Freiburg, 79110 Freiburg, Germany
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Kruse P, Brandes G, Hemeling H, Huang Z, Wrede C, Hegermann J, Vlachos A, Lenz M. Synaptopodin Regulates Denervation-Induced Plasticity at Hippocampal Mossy Fiber Synapses. Cells 2024; 13:114. [PMID: 38247806 PMCID: PMC10814840 DOI: 10.3390/cells13020114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/17/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024] Open
Abstract
Neurological diseases can lead to the denervation of brain regions caused by demyelination, traumatic injury or cell death. The molecular and structural mechanisms underlying lesion-induced reorganization of denervated brain regions, however, are a matter of ongoing investigation. In order to address this issue, we performed an entorhinal cortex lesion (ECL) in mouse organotypic entorhino-hippocampal tissue cultures of both sexes and studied denervation-induced plasticity of mossy fiber synapses, which connect dentate granule cells (dGCs) with CA3 pyramidal cells (CA3-PCs) and play important roles in learning and memory formation. Partial denervation caused a strengthening of excitatory neurotransmission in dGCs, CA3-PCs and their direct synaptic connections, as revealed by paired recordings (dGC-to-CA3-PC). These functional changes were accompanied by ultrastructural reorganization of mossy fiber synapses, which regularly contain the plasticity-regulating protein synaptopodin and the spine apparatus organelle. We demonstrate that the spine apparatus organelle and synaptopodin are related to ribosomes in close proximity to synaptic sites and reveal a synaptopodin-related transcriptome. Notably, synaptopodin-deficient tissue preparations that lack the spine apparatus organelle failed to express lesion-induced synaptic adjustments. Hence, synaptopodin and the spine apparatus organelle play a crucial role in regulating lesion-induced synaptic plasticity at hippocampal mossy fiber synapses.
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Affiliation(s)
- Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Gudrun Brandes
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany
| | - Hanna Hemeling
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Zhong Huang
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, 30625 Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, 30625 Hannover, Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, 30625 Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, 30625 Hannover, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, 79104 Freiburg, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany
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Malik SC, Lin JD, Ziegler-Waldkirch S, Tholen S, Deshpande SS, Schwabenland M, Schilling O, Vlachos A, Meyer-Luehmann M, Schachtrup C. Tpr Misregulation in Hippocampal Neural Stem Cells in Mouse Models of Alzheimer's Disease. Cells 2023; 12:2757. [PMID: 38067185 PMCID: PMC10706632 DOI: 10.3390/cells12232757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/19/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Nuclear pore complexes (NPCs) are highly dynamic macromolecular protein structures that facilitate molecular exchange across the nuclear envelope. Aberrant NPC functioning has been implicated in neurodegeneration. The translocated promoter region (Tpr) is a critical scaffolding nucleoporin (Nup) of the nuclear basket, facing the interior of the NPC. However, the role of Tpr in adult neural stem/precursor cells (NSPCs) in Alzheimer's disease (AD) is unknown. Using super-resolution (SR) and electron microscopy, we defined the different subcellular localizations of Tpr and phospho-Tpr (P-Tpr) in NSPCs in vitro and in vivo. Elevated Tpr expression and reduced P-Tpr nuclear localization accompany NSPC differentiation along the neurogenic lineage. In 5xFAD mice, an animal model of AD, increased Tpr expression in DCX+ hippocampal neuroblasts precedes increased neurogenesis at an early stage, before the onset of amyloid-β plaque formation. Whereas nuclear basket Tpr interacts with chromatin modifiers and NSPC-related transcription factors, P-Tpr interacts and co-localizes with cyclin-dependent kinase 1 (Cdk1) at the nuclear chromatin of NSPCs. In hippocampal NSPCs in a mouse model of AD, aberrant Tpr expression was correlated with altered NPC morphology and counts, and Tpr was aberrantly expressed in postmortem human brain samples from patients with AD. Thus, we propose that altered levels and subcellular localization of Tpr in CNS disease affect Tpr functionality, which in turn regulates the architecture and number of NSPC NPCs, possibly leading to aberrant neurogenesis.
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Affiliation(s)
- Subash C. Malik
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Jia-Di Lin
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Stephanie Ziegler-Waldkirch
- Department of Neurology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (S.Z.-W.); (M.M.-L.)
| | - Stefan Tholen
- Institute of Surgical Pathology, Medical Center, University of Freiburg, 79106 Freiburg, Germany; (S.T.); (O.S.)
| | - Sachin S. Deshpande
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Marius Schwabenland
- Institute of Neuropathology, University of Freiburg, 79106 Freiburg, Germany
| | - Oliver Schilling
- Institute of Surgical Pathology, Medical Center, University of Freiburg, 79106 Freiburg, Germany; (S.T.); (O.S.)
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
- Center BrainLinks-BrainTools, University of Freiburg, 79110 Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Melanie Meyer-Luehmann
- Department of Neurology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (S.Z.-W.); (M.M.-L.)
- Center for Basics in Neuromodulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Christian Schachtrup
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Center for Basics in Neuromodulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
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Shaner S, Lu H, Lenz M, Garg S, Vlachos A, Asplund M. Brain stimulation-on-a-chip: a neuromodulation platform for brain slices. Lab Chip 2023; 23:4967-4985. [PMID: 37909911 PMCID: PMC10661668 DOI: 10.1039/d3lc00492a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 10/15/2023] [Indexed: 11/03/2023]
Abstract
Electrical stimulation of ex vivo brain tissue slices has been a method used to understand mechanisms imparted by transcranial direct current stimulation (tDCS), but there are significant direct current electric field (dcEF) dosage and electrochemical by-product concerns in conventional experimental setups that may impact translational findings. Therefore, we developed an on-chip platform with fluidic, electrochemical, and magnetically-induced spatial control. Fluidically, the chamber geometrically confines precise dcEF delivery to the enclosed brain slice and allows for tissue recovery in order to monitor post-stimulation effects. Electrochemically, conducting hydrogel electrodes mitigate stimulation-induced faradaic reactions typical of commonly-used metal electrodes. Magnetically, we applied ferromagnetic substrates beneath the tissue and used an external permanent magnet to enable in situ rotational control in relation to the dcEF. By combining the microfluidic chamber with live-cell calcium imaging and electrophysiological recordings, we showcased the potential to study the acute and lasting effects of dcEFs with the potential of providing multi-session stimulation. This on-chip bioelectronic platform presents a modernized yet simple solution to electrically stimulate explanted tissue by offering more environmental control to users, which unlocks new opportunities to conduct thorough brain stimulation mechanistic investigations.
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Affiliation(s)
- Sebastian Shaner
- Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg im Breisgau, Germany
- BrainLinks-BrainTools Center, University of Freiburg, Georges-Köhler-Allee 201, 79110 Freiburg im Breisgau, Germany
| | - Han Lu
- BrainLinks-BrainTools Center, University of Freiburg, Georges-Köhler-Allee 201, 79110 Freiburg im Breisgau, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albertstraße 17, 79104 Freiburg im Breisgau, Germany.
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albertstraße 17, 79104 Freiburg im Breisgau, Germany.
- Hannover Medical School, Institute of Neuroanatomy and Cell Biology, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Shreyash Garg
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albertstraße 17, 79104 Freiburg im Breisgau, Germany.
- MSc Neuroscience Program, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg im Breisgau, Germany
| | - Andreas Vlachos
- BrainLinks-BrainTools Center, University of Freiburg, Georges-Köhler-Allee 201, 79110 Freiburg im Breisgau, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albertstraße 17, 79104 Freiburg im Breisgau, Germany.
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Maria Asplund
- Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg im Breisgau, Germany
- BrainLinks-BrainTools Center, University of Freiburg, Georges-Köhler-Allee 201, 79110 Freiburg im Breisgau, Germany
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Chalmersplatsen 4, 41258 Gothenburg, Sweden.
- Division of Nursing and Medical Technology, Luleå University of Technology, 79187 Luleå, Sweden
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Albertstraße 19, 79104 Freiburg im Breisgau, Germany
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Kuliesiute U, Joseph K, Straehle J, Madapusi Ravi V, Kueckelhaus J, Kada Benotmane J, Zhang J, Vlachos A, Beck J, Schnell O, Neniskyte U, Heiland DH. Sialic acid metabolism orchestrates transcellular connectivity and signaling in glioblastoma. Neuro Oncol 2023; 25:1963-1975. [PMID: 37288604 PMCID: PMC10628944 DOI: 10.1093/neuonc/noad101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Indexed: 06/09/2023] Open
Abstract
BACKGROUND In glioblastoma (GBM), the effects of altered glycocalyx are largely unexplored. The terminal moiety of cell coating glycans, sialic acid, is of paramount importance for cell-cell contacts. However, sialic acid turnover in gliomas and its impact on tumor networks remain unknown. METHODS We streamlined an experimental setup using organotypic human brain slice cultures as a framework for exploring brain glycobiology, including metabolic labeling of sialic acid moieties and quantification of glycocalyx changes. By live, 2-photon and high-resolution microscopy we have examined morphological and functional effects of altered sialic acid metabolism in GBM. By calcium imaging we investigated the effects of the altered glycocalyx on a functional level of GBM networks. RESULTS The visualization and quantitative analysis of newly synthesized sialic acids revealed a high rate of de novo sialylation in GBM cells. Sialyltrasferases and sialidases were highly expressed in GBM, indicating that significant turnover of sialic acids is involved in GBM pathology. Inhibition of either sialic acid biosynthesis or desialylation affected the pattern of tumor growth and lead to the alterations in the connectivity of glioblastoma cells network. CONCLUSIONS Our results indicate that sialic acid is essential for the establishment of GBM tumor and its cellular network. They highlight the importance of sialic acid for glioblastoma pathology and suggest that dynamics of sialylation have the potential to be targeted therapeutically.
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Affiliation(s)
- Ugne Kuliesiute
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
- VU LSC-EMBL Partnership for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Kevin Joseph
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Jakob Straehle
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Vidhya Madapusi Ravi
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Jan Kueckelhaus
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Jasim Kada Benotmane
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Junyi Zhang
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Juergen Beck
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Schnell
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
| | - Urte Neniskyte
- Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
- VU LSC-EMBL Partnership for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Dieter Henrik Heiland
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Freiburg University, Freiburg, Germany
- Department of Neurological Surgery, Lou and Jean Malnati Brain Tumor Institute, Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
- Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center—University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK), partner siteFreiburg
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Anil S, Lu H, Rotter S, Vlachos A. Repetitive transcranial magnetic stimulation (rTMS) triggers dose-dependent homeostatic rewiring in recurrent neuronal networks. PLoS Comput Biol 2023; 19:e1011027. [PMID: 37956202 PMCID: PMC10681319 DOI: 10.1371/journal.pcbi.1011027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 11/27/2023] [Accepted: 10/11/2023] [Indexed: 11/15/2023] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique used to induce neuronal plasticity in healthy individuals and patients. Designing effective and reproducible rTMS protocols poses a major challenge in the field as the underlying biomechanisms of long-term effects remain elusive. Current clinical protocol designs are often based on studies reporting rTMS-induced long-term potentiation or depression of synaptic transmission. Herein, we employed computational modeling to explore the effects of rTMS on long-term structural plasticity and changes in network connectivity. We simulated a recurrent neuronal network with homeostatic structural plasticity among excitatory neurons, and demonstrated that this mechanism was sensitive to specific parameters of the stimulation protocol (i.e., frequency, intensity, and duration of stimulation). Particularly, the feedback-inhibition initiated by network stimulation influenced the net stimulation outcome and hindered the rTMS-induced structural reorganization, highlighting the role of inhibitory networks. These findings suggest a novel mechanism for the lasting effects of rTMS, i.e., rTMS-induced homeostatic structural plasticity, and highlight the importance of network inhibition in careful protocol design, standardization, and optimization of stimulation.
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Affiliation(s)
- Swathi Anil
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Han Lu
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Stefan Rotter
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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9
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Frase S, Steddin J, Paschen E, Lenz M, Conforti P, Haas CA, Vlachos A, Schachtrup C, Hosp JA. Dense dopaminergic innervation of the peri-infarct cortex despite dopaminergic cell loss after a pure motor-cortical stroke in rats. J Neurochem 2023; 167:427-440. [PMID: 37735852 DOI: 10.1111/jnc.15970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 08/28/2023] [Accepted: 09/12/2023] [Indexed: 09/23/2023]
Abstract
After ischemic stroke, the cortex directly adjacent to the ischemic core (i.e., the peri-infarct cortex, PIC) undergoes plastic changes that facilitate motor recovery. Dopaminergic signaling is thought to support this process. However, ischemic stroke also leads to the remote degeneration of dopaminergic midbrain neurons, possibly interfering with this beneficial effect. In this study, we assessed the reorganization of dopaminergic innervation of the PIC in a rat model of focal cortical stroke. Adult Sprague-Dawley rats either received a photothrombotic stroke (PTS) in the primary motor cortex (M1) or a sham operation. 30 days after PTS or sham procedure, the retrograde tracer Micro Ruby (MR) was injected into the PIC of stroke animals or into homotopic cortical areas of matched sham rats. Thus, dopaminergic midbrain neurons projecting into the PIC were identified based on MR signal and immunoreactivity against tyrosine hydroxylase (TH), a marker for dopaminergic neurons. The density of dopaminergic innervation within the PIC was assessed by quantification of dopaminergic boutons indicated by TH-immunoreactivity. Regarding postsynaptic processes, expression of dopamine receptors (D1- and D2) and a marker of the functional signal cascade (DARPP-32) were visualized histologically. Despite a 25% ipsilesional loss of dopaminergic midbrain neurons after PTS, the number and spatial distribution of dopaminergic neurons projecting to the PIC was not different compared to sham controls. Moreover, the density of dopaminergic innervation in the PIC was significantly higher than in homotopic cortical areas of the sham group. Within the PIC, D1-receptors were expressed in neurons, whereas D2-receptors were confined to astrocytes. The intensity of D1- and DARPP-32 expression appeared to be higher in the PIC compared to the contralesional homotopic cortex. Our data suggest a sprouting of dopaminergic fibers into the PIC and point to a role for dopaminergic signaling in reparative mechanisms post-stroke, potentially related to recovery.
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Affiliation(s)
- Sibylle Frase
- Department of Neurology and Neuroscience, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julius Steddin
- Department of Neurology and Neuroscience, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Enya Paschen
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pasquale Conforti
- Department of Molecular Embryology, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christian Schachtrup
- Department of Molecular Embryology, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jonas A Hosp
- Department of Neurology and Neuroscience, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Galanis C, Neuhaus L, Hananeia N, Turi Z, Jedlicka P, Vlachos A. Axon morphology and intrinsic cellular properties determine repetitive transcranial magnetic stimulation threshold for plasticity. bioRxiv 2023:2023.09.25.559399. [PMID: 37808716 PMCID: PMC10557586 DOI: 10.1101/2023.09.25.559399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a widely used therapeutic tool in neurology and psychiatry, but its cellular and molecular mechanisms are not fully understood. Standardizing stimulus parameters, specifically electric field strength and direction, is crucial in experimental and clinical settings. It enables meaningful comparisons across studies and facilitating the translation of findings into clinical practice. However, the impact of biophysical properties inherent to the stimulated neurons and networks on the outcome of rTMS protocols remains not well understood. Consequently, achieving standardization of biological effects across different brain regions and subjects poses a significant challenge. This study compared the effects of 10 Hz repetitive magnetic stimulation (rMS) in entorhino-hippocampal tissue cultures from mice and rats, providing insights into the impact of the same stimulation protocol on similar neuronal networks under standardized conditions. We observed the previously described plastic changes in excitatory and inhibitory synaptic strength of CA1 pyramidal neurons in both mouse and rat tissue cultures, but a higher stimulation intensity was required for the induction of rMS-induced synaptic plasticity in rat tissue cultures. Through systematic comparison of neuronal structural and functional properties and computational modeling, we found that morphological parameters of CA1 pyramidal neurons alone are insufficient to explain the observed differences between the groups. However, axon morphologies of individual cells played a significant role in determining activation thresholds. Notably, differences in intrinsic cellular properties were sufficient to account for the 10 % higher intensity required for the induction of synaptic plasticity in the rat tissue cultures. These findings demonstrate the critical importance of axon morphology and intrinsic cellular properties in predicting the plasticity effects of rTMS, carrying valuable implications for the development of computer models aimed at predicting and standardizing the biological effects of rTMS.
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Zhang J, Straehle J, Joseph K, Neidert N, Behringer S, Göldner J, Vlachos A, Prinz M, Fung C, Beck J, Schnell O, Heiland DH, Ravi VM. Isolation and profiling of viable tumor cells from human ex vivo glioblastoma cultures through single-cell transcriptomics. STAR Protoc 2023; 4:102383. [PMID: 37393609 PMCID: PMC10328984 DOI: 10.1016/j.xpro.2023.102383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/06/2023] [Accepted: 05/25/2023] [Indexed: 07/04/2023] Open
Abstract
Single-cell RNA-sequencing (scRNA-seq) is becoming a ubiquitous method in profiling the cellular transcriptomes of both malignant and non-malignant cells from the human brain. Here, we present a protocol to isolate viable tumor cells from human ex vivo glioblastoma cultures for single-cell transcriptomic analysis. We describe steps including surgical tissue collection, sectioning, culturing, primary tumor cells inoculation, growth tracking, fluorescence-based cell sorting, and population-enriched scRNA-seq. This comprehensive methodology empowers in-depth understanding of brain tumor biology at the single-cell level. For complete details on the use and execution of this protocol, please refer to Ravi et al.1.
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Affiliation(s)
- Junyi Zhang
- 3D-Brain Models for Neurodegenerative Diseases, Medical Center, University of Freiburg, Freiburg, Germany; Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany; Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Translational NeuroOncology Research Group, Medical Center - University of Freiburg, Freiburg, Germany
| | - Jakob Straehle
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Center of Advanced Surgical Tissue Analysis (CAST), University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Kevin Joseph
- NeuroEngineering Laboratory, Medical Centre, University of Freiburg, Freiburg, Germany; Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Center of Advanced Surgical Tissue Analysis (CAST), University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Translational NeuroOncology Research Group, Medical Center - University of Freiburg, Freiburg, Germany
| | - Nicolas Neidert
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Simon Behringer
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jonathan Göldner
- 3D-Brain Models for Neurodegenerative Diseases, Medical Center, University of Freiburg, Freiburg, Germany; Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany; Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Translational NeuroOncology Research Group, Medical Center - University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Center, University of Freiburg, Freiburg, Germany; Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for NeuroModulation (NeuroModul), University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for NeuroModulation (NeuroModul), University of Freiburg, Freiburg, Germany; Institute of Neuropathology, Medical Center - University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Christian Fung
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Center of Advanced Surgical Tissue Analysis (CAST), University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany; Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center- University of Freiburg, Freiburg, Germany
| | - Oliver Schnell
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Center of Advanced Surgical Tissue Analysis (CAST), University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Translational NeuroOncology Research Group, Medical Center - University of Freiburg, Freiburg, Germany
| | - Dieter Henrik Heiland
- Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany; Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Center of Advanced Surgical Tissue Analysis (CAST), University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Translational NeuroOncology Research Group, Medical Center - University of Freiburg, Freiburg, Germany; Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center- University of Freiburg, Freiburg, Germany; German Cancer Consortium (DKTK), Partner Site Freiburg; Department of Neurological Surgery, Lou and Jean Malnati Brain Tumor Institute, Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Vidhya M Ravi
- 3D-Brain Models for Neurodegenerative Diseases, Medical Center, University of Freiburg, Freiburg, Germany; Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany; Center of Advanced Surgical Tissue Analysis (CAST), University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany; Translational NeuroOncology Research Group, Medical Center - University of Freiburg, Freiburg, Germany; Freiburg Institute of Advanced Studies (FRIAS), Freiburg, Germany.
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Lenz M, Eichler A, Kruse P, Galanis C, Kleidonas D, Andrieux G, Boerries M, Jedlicka P, Müller U, Deller T, Vlachos A. The Amyloid Precursor Protein Regulates Synaptic Transmission at Medial Perforant Path Synapses. J Neurosci 2023; 43:5290-5304. [PMID: 37369586 PMCID: PMC10359033 DOI: 10.1523/jneurosci.1824-22.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 05/20/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
The perforant path provides the primary cortical excitatory input to the hippocampus. Because of its important role in information processing and coding, entorhinal projections to the dentate gyrus have been studied in considerable detail. Nevertheless, synaptic transmission between individual connected pairs of entorhinal stellate cells and dentate granule cells remains to be characterized. Here, we have used mouse organotypic entorhino-hippocampal tissue cultures of either sex, in which the entorhinal cortex (EC) to dentate granule cell (GC; EC-GC) projection is present, and EC-GC pairs can be studied using whole-cell patch-clamp recordings. By using cultures of wild-type mice, the properties of EC-GC synapses formed by afferents from the lateral and medial entorhinal cortex were compared, and differences in short-term plasticity were identified. As the perforant path is severely affected in Alzheimer's disease, we used tissue cultures of amyloid precursor protein (APP)-deficient mice to examine the role of APP at this synapse. APP deficiency altered excitatory neurotransmission at medial perforant path synapses, which was accompanied by transcriptomic and ultrastructural changes. Moreover, presynaptic but not postsynaptic APP deletion through the local injection of Cre-expressing adeno-associated viruses in conditional APPflox/flox tissue cultures increased the neurotransmission efficacy at perforant path synapses. In summary, these data suggest a physiological role for presynaptic APP at medial perforant path synapses that may be adversely affected under altered APP processing conditions.SIGNIFICANCE STATEMENT The hippocampus receives input from the entorhinal cortex via the perforant path. These projections to hippocampal dentate granule cells are of utmost importance for learning and memory formation. Although there is detailed knowledge about perforant path projections, the functional synaptic properties at the level of individual connected pairs of neurons are not well understood. In this study, we investigated the role of APP in mediating functional properties and transmission rules in individually connected neurons using paired whole-cell patch-clamp recordings and genetic tools in organotypic tissue cultures. Our results show that presynaptic APP expression limits excitatory neurotransmission via the perforant path, which could be compromised in pathologic conditions such as Alzheimer's disease.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Hannover Medical School, Institute of Neuroanatomy and Cell Biology, 30625 Hannover, Germany
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Dimitrios Kleidonas
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Geoffroy Andrieux
- Institute of Medical Bioinformatics and Systems Medicine, Medical Center, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Melanie Boerries
- Institute of Medical Bioinformatics and Systems Medicine, Medical Center, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- German Cancer Consortium, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Peter Jedlicka
- Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
- Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main, Germany
| | - Ulrike Müller
- Institute of Pharmacy and Molecular Biotechnology, Functional Genomics, Ruprecht-Karls University Heidelberg, 69120 Heidelberg, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, 79104 Freiburg, Germany
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Schröder JK, Abdel-Hafiz L, Ali AAH, Cousin TC, Hallenberger J, Rodrigues Almeida F, Anstötz M, Lenz M, Vlachos A, von Gall C, Tundo-Lavalle F. Effects of the Light/Dark Phase and Constant Light on Spatial Working Memory and Spine Plasticity in the Mouse Hippocampus. Cells 2023; 12:1758. [PMID: 37443792 PMCID: PMC10340644 DOI: 10.3390/cells12131758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/22/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Circadian rhythms in behavior and physiology such as rest/activity and hormones are driven by an internal clock and persist in the absence of rhythmic environmental cues. However, the period and phase of the internal clock are entrained by the environmental light/dark cycle. Consequently, aberrant lighting conditions, which are increasing in modern society, have a strong impact on rhythmic body and brain functions. Mice were exposed to three different lighting conditions, 12 h light/12 h dark cycle (LD), constant darkness (DD), and constant light (LL), to study the effects of the light/dark cycle and aberrant lighting on the hippocampus, a critical structure for temporal and spatial memory formation and navigation. Locomotor activity and plasma corticosterone levels were analyzed as readouts for circadian rhythms. Spatial working memory via Y-maze, spine morphology of Golgi-Cox-stained hippocampi, and plasticity of excitatory synapses, measured by number and size of synaptopodin and GluR1-immunreactive clusters, were analyzed. Our results indicate that the light/dark cycle drives diurnal differences in synaptic plasticity in hippocampus. Moreover, spatial working memory, spine density, and size and number of synaptopodin and GluR1 clusters were reduced in LL, while corticosterone levels were increased. This indicates that acute constant light affects hippocampal function and synaptic plasticity.
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Affiliation(s)
- Jane K. Schröder
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
- Department of Pediatric Hematology and Oncology, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Laila Abdel-Hafiz
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
| | - Amira A. H. Ali
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
- Department of Human Anatomy and Embryology, Faculty of Medicine, Mansoura University, El-Gomhoria St. 1, Mansoura 35516, Egypt
| | - Teresa C. Cousin
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
| | - Johanna Hallenberger
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
| | - Filipe Rodrigues Almeida
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
| | - Max Anstötz
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
| | - Maximilian Lenz
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany;
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
| | - Charlotte von Gall
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
| | - Federica Tundo-Lavalle
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany; (J.K.S.); (L.A.-H.); (A.A.H.A.); (T.C.C.); (J.H.); (F.R.A.); (M.A.); (F.T.-L.)
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Kleidonas D, Kirsch M, Andrieux G, Pfeifer D, Boerries M, Vlachos A. Microglia modulate TNFα-mediated synaptic plasticity. Glia 2023. [PMID: 37208965 DOI: 10.1002/glia.24383] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 04/18/2023] [Accepted: 05/02/2023] [Indexed: 05/21/2023]
Abstract
The pro-inflammatory cytokine tumor necrosis factor α (TNFα) tunes the capacity of neurons to express synaptic plasticity. It remains, however, unclear how TNFα mediates synaptic positive (=change) and negative (=stability) feedback mechanisms. We assessed effects of TNFα on microglia activation and synaptic transmission onto CA1 pyramidal neurons of mouse organotypic entorhino-hippocampal tissue cultures. TNFα mediated changes in excitatory and inhibitory neurotransmission in a concentration-dependent manner, where low concentration strengthened glutamatergic neurotransmission via synaptic accumulation of GluA1-only-containing AMPA receptors and higher concentration increased inhibition. The latter induced the synaptic accumulation of GluA1-only-containing AMPA receptors as well. However, activated, pro-inflammatory microglia mediated a homeostatic adjustment of excitatory synapses, that is, an initial increase in excitatory synaptic strength at 3 h returned to baseline within 24 h, while inhibitory neurotransmission increased. In microglia-depleted tissue cultures, synaptic strengthening triggered by high levels of TNFα persisted and the impact of TNFα on inhibitory neurotransmission was still observed and dependent on its concentration. These findings underscore the essential role of microglia in TNFα-mediated synaptic plasticity. They suggest that pro-inflammatory microglia mediate synaptic homeostasis, that is, negative feedback mechanisms, which may affect the ability of neurons to express further plasticity, thereby emphasizing the importance of microglia as gatekeepers of synaptic change and stability.
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Affiliation(s)
- Dimitrios Kleidonas
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Matthias Kirsch
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Geoffroy Andrieux
- Institute of Medical Bioinformatics and Systems Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dietmar Pfeifer
- Department of Hematology, Oncology and Stem Cell Transplantation, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Melanie Boerries
- Institute of Medical Bioinformatics and Systems Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Schwabenland M, Mossad O, Sievert A, Peres AG, Ringel E, Baasch S, Kolter J, Cascone G, Dokalis N, Vlachos A, Ruzsics Z, Henneke P, Prinz M, Blank T. Neonatal immune challenge poses a sex-specific risk for epigenetic microglial reprogramming and behavioral impairment. Nat Commun 2023; 14:2721. [PMID: 37169749 PMCID: PMC10175500 DOI: 10.1038/s41467-023-38373-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/27/2023] [Indexed: 05/13/2023] Open
Abstract
While the precise processes underlying a sex bias in the development of central nervous system (CNS) disorders are unknown, there is growing evidence that an early life immune activation can contribute to the disease pathogenesis. When we mimicked an early systemic viral infection or applied murine cytomegalovirus (MCMV) systemically in neonatal female and male mice, only male adolescent mice presented behavioral deficits, including reduced social behavior and cognition. This was paralleled by an increased amount of infiltrating T cells in the brain parenchyma, enhanced interferon-γ (IFNγ) signaling, and epigenetic reprogramming of microglial cells. These microglial cells showed increased phagocytic activity, which resulted in abnormal loss of excitatory synapses within the hippocampal brain region. None of these alterations were seen in female adolescent mice. Our findings underscore the early postnatal period's susceptibility to cause sex-dependent long-term CNS deficiencies following infections.
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Affiliation(s)
- Marius Schwabenland
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Omar Mossad
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Annika Sievert
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Adam G Peres
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Elena Ringel
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sebastian Baasch
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julia Kolter
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Giulia Cascone
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nikolaos Dokalis
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Zsolt Ruzsics
- Institute for Virology, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | - Philipp Henneke
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Pediatrics and Adolescent Medicine, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Thomas Blank
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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16
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Straehle J, Ravi VM, Heiland DH, Galanis C, Lenz M, Zhang J, Neidert NN, El Rahal A, Vasilikos I, Kellmeyer P, Scheiwe C, Klingler JH, Fung C, Vlachos A, Beck J, Schnell O. Technical report: surgical preparation of human brain tissue for clinical and basic research. Acta Neurochir (Wien) 2023; 165:1461-1471. [PMID: 37147485 DOI: 10.1007/s00701-023-05611-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/21/2023] [Indexed: 05/07/2023]
Abstract
BACKGROUND The study of the distinct structure and function of the human central nervous system, both in healthy and diseased states, is becoming increasingly significant in the field of neuroscience. Typically, cortical and subcortical tissue is discarded during surgeries for tumors and epilepsy. Yet, there is a strong encouragement to utilize this tissue for clinical and basic research in humans. Here, we describe the technical aspects of the microdissection and immediate handling of viable human cortical access tissue for basic and clinical research, highlighting the measures needed to be taken in the operating room to ensure standardized procedures and optimal experimental results. METHODS In multiple rounds of experiments (n = 36), we developed and refined surgical principles for the removal of cortical access tissue. The specimens were immediately immersed in cold carbogenated N-methyl-D-glucamine-based artificial cerebrospinal fluid for electrophysiology and electron microscopy experiments or specialized hibernation medium for organotypic slice cultures. RESULTS The surgical principles of brain tissue microdissection were (1) rapid preparation (<1 min), (2) maintenance of the cortical axis, (3) minimization of mechanical trauma to sample, (4) use of pointed scalpel blade, (5) avoidance of cauterization and blunt preparation, (6) constant irrigation, and (7) retrieval of the sample without the use of forceps or suction. After a single round of introduction to these principles, multiple surgeons adopted the technique for samples with a minimal dimension of 5 mm spanning all cortical layers and subcortical white matter. Small samples (5-7 mm) were ideal for acute slice preparation and electrophysiology. No adverse events from sample resection were observed. CONCLUSION The microdissection technique of human cortical access tissue is safe and easily adoptable into the routine of neurosurgical procedures. The standardized and reliable surgical extraction of human brain tissue lays the foundation for human-to-human translational research on human brain tissue.
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Affiliation(s)
- J Straehle
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - V M Ravi
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Freiburg Institute of Advanced Studies (FRIAS), Freiburg, Germany
| | - D H Heiland
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Neurological Surgery, Lou and Jean Malnati Brain Tumor Institute, Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - C Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - M Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Junyi Zhang
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - N N Neidert
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - A El Rahal
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - I Vasilikos
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - P Kellmeyer
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - C Scheiwe
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - J H Klingler
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - C Fung
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - A Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links - Brain Tools, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - J Beck
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - O Schnell
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- Center for Advanced Surgical Tissue Analysis (CAST), Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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17
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Frase S, Steddin J, Paschen E, Haas C, Lenz M, Vlachos A, Hosp J. P-97 Dense dopaminergic innervation of the peri-infarct cortex despite dopaminergic cell loss after a pure motor-cortical stroke in rats. Clin Neurophysiol 2023. [DOI: 10.1016/j.clinph.2023.02.114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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18
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Eichler A, Kleidonas D, Turi Z, Fliegauf M, Kirsch M, Pfeifer D, Masuda T, Prinz M, Lenz M, Vlachos A. Microglial Cytokines Mediate Plasticity Induced by 10 Hz Repetitive Magnetic Stimulation. J Neurosci 2023; 43:3042-3060. [PMID: 36977586 PMCID: PMC10146500 DOI: 10.1523/jneurosci.2226-22.2023] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 02/15/2023] [Accepted: 03/10/2023] [Indexed: 03/29/2023] Open
Abstract
Microglia-the resident immune cells of the central nervous system-sense the activity of neurons and regulate physiological brain functions. They have been implicated in the pathology of brain diseases associated with alterations in neural excitability and plasticity. However, experimental and therapeutic approaches that modulate microglia function in a brain-region-specific manner have not been established. In this study, we tested for the effects of repetitive transcranial magnetic stimulation (rTMS), a clinically employed non-invasive brain stimulation technique, on microglia-mediated synaptic plasticity. 10 Hz electromagnetic stimulation triggered a release of plasticity-promoting cytokines from microglia in mouse organotypic brain tissue cultures of both sexes, while no significant changes in microglial morphology or microglia dynamics were observed. Indeed, substitution of tumor necrosis factor alpha (TNFα) and interleukin 6 (IL6) preserved synaptic plasticity induced by 10 Hz stimulation in the absence of microglia. Consistent with these findings, in vivo depletion of microglia abolished rTMS-induced changes in neurotransmission in the medial prefrontal cortex (mPFC) of anesthetized mice of both sexes. We conclude that rTMS affects neural excitability and plasticity by modulating the release of cytokines from microglia.Significance Statement:Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that induces cortical plasticity. Despite its wide use in neuroscience and clinical practice (e.g., depression treatment) the cellular and molecular mechanisms of rTMS-mediated plasticity remain not well understood. Herein, we report an important role of microglia and plasticity-promoting cytokines in synaptic plasticity induced by 10 Hz rTMS in organotypic slice cultures and anesthetized mice, thereby identifying microglia-mediated synaptic adaptation as a target of rTMS-based interventions.
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19
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Anil S, Lu H, Rotter S, Vlachos A. Repetitive transcranial magnetic stimulation (rTMS) triggers dose-dependent homeostatic rewiring in recurrent neuronal networks. bioRxiv 2023:2023.03.20.533396. [PMID: 36993387 PMCID: PMC10055183 DOI: 10.1101/2023.03.20.533396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique used to induce neuronal plasticity in healthy individuals and patients. Designing effective and reproducible rTMS protocols poses a major challenge in the field as the underlying biomechanisms remain elusive. Current clinical protocol designs are often based on studies reporting rTMS-induced long-term potentiation or depression of synaptic transmission. Herein, we employed computational modeling to explore the effects of rTMS on long-term structural plasticity and changes in network connectivity. We simulated a recurrent neuronal network with homeostatic structural plasticity between excitatory neurons, and demonstrated that this mechanism was sensitive to specific parameters of the stimulation protocol (i.e., frequency, intensity, and duration of stimulation). The feedback-inhibition initiated by network stimulation influenced the net stimulation outcome and hindered the rTMS-induced homeostatic structural plasticity, highlighting the role of inhibitory networks. These findings suggest a novel mechanism for the lasting effects of rTMS, i.e., rTMS-induced homeostatic structural plasticity, and highlight the importance of network inhibition in careful protocol design, standardization, and optimization of stimulation.
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Affiliation(s)
- Swathi Anil
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Han Lu
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Stefan Rotter
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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20
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Lenz M, Eichler A, Kruse P, Stöhr P, Kleidonas D, Galanis C, Lu H, Vlachos A. Denervated mouse CA1 pyramidal neurons express homeostatic synaptic plasticity following entorhinal cortex lesion. Front Mol Neurosci 2023; 16:1148219. [PMID: 37122623 PMCID: PMC10130538 DOI: 10.3389/fnmol.2023.1148219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/14/2023] [Indexed: 05/02/2023] Open
Abstract
Structural, functional, and molecular reorganization of denervated neural networks is often observed in neurological conditions. The loss of input is accompanied by homeostatic synaptic adaptations, which can affect the reorganization process. A major challenge of denervation-induced homeostatic plasticity operating in complex neural networks is the specialization of neuronal inputs. It remains unclear whether neurons respond similarly to the loss of distinct inputs. Here, we used in vitro entorhinal cortex lesion (ECL) and Schaffer collateral lesion (SCL) in mouse organotypic entorhino-hippocampal tissue cultures to study denervation-induced plasticity of CA1 pyramidal neurons. We observed microglia accumulation, presynaptic bouton degeneration, and a reduction in dendritic spine numbers in the denervated layers 3 days after SCL and ECL. Transcriptome analysis of the CA1 region revealed complex changes in differential gene expression following SCL and ECL compared to non-lesioned controls with a specific enrichment of differentially expressed synapse-related genes observed after ECL. Consistent with this finding, denervation-induced homeostatic plasticity of excitatory synapses was observed 3 days after ECL but not after SCL. Chemogenetic silencing of the EC but not CA3 confirmed the pathway-specific induction of homeostatic synaptic plasticity in CA1. Additionally, increased RNA oxidation was observed after SCL and ECL. These results reveal important commonalities and differences between distinct pathway lesions and demonstrate a pathway-specific induction of denervation-induced homeostatic synaptic plasticity.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- *Correspondence: Maximilian Lenz,
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Phyllis Stöhr
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dimitrios Kleidonas
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Han Lu
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Andreas Vlachos,
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21
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Turi Z, Hananeia N, Shirinpour S, Opitz A, Jedlicka P, Vlachos A. Dosing Transcranial Magnetic Stimulation of the Primary Motor and Dorsolateral Prefrontal Cortices With Multi-Scale Modeling. Front Neurosci 2022; 16:929814. [PMID: 35898411 PMCID: PMC9309210 DOI: 10.3389/fnins.2022.929814] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/27/2022] [Indexed: 11/15/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) can depolarize cortical neurons through the intact skin and skull. The characteristics of the induced electric field (E-field) have a major impact on specific outcomes of TMS. Using multi-scale computational modeling, we explored whether the stimulation parameters derived from the primary motor cortex (M1) induce comparable macroscopic E-field strengths and subcellular/cellular responses in the dorsolateral prefrontal cortex (DLPFC). To this aim, we calculated the TMS-induced E-field in 16 anatomically realistic head models and simulated the changes in membrane voltage and intracellular calcium levels of morphologically and biophysically realistic human pyramidal cells in the M1 and DLPFC. We found that the conventional intensity selection methods (i.e., motor threshold and fixed intensities) produce variable macroscopic E-fields. Consequently, it was challenging to produce comparable subcellular/cellular responses across cortical regions with distinct folding characteristics. Prospectively, personalized stimulation intensity selection could standardize the E-fields and the subcellular/cellular responses to repetitive TMS across cortical regions and individuals. The suggested computational approach points to the shortcomings of the conventional intensity selection methods used in clinical settings. We propose that multi-scale modeling has the potential to overcome some of these limitations and broaden our understanding of the neuronal mechanisms for TMS.
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Affiliation(s)
- Zsolt Turi
- Department of Neuroanatomy, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany
| | - Nicholas Hananeia
- Faculty of Medicine, Interdisciplinary Centre for 3Rs in Animal Research, Justus-Liebig-University, Giessen, Germany
| | - Sina Shirinpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Peter Jedlicka
- Faculty of Medicine, Interdisciplinary Centre for 3Rs in Animal Research, Justus-Liebig-University, Giessen, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- *Correspondence: Andreas Vlachos
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22
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Rosado J, Bui VD, Haas CA, Beck J, Queisser G, Vlachos A. Calcium modeling of spine apparatus-containing human dendritic spines demonstrates an “all-or-nothing” communication switch between the spine head and dendrite. PLoS Comput Biol 2022; 18:e1010069. [PMID: 35468131 PMCID: PMC9071165 DOI: 10.1371/journal.pcbi.1010069] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 05/05/2022] [Accepted: 03/30/2022] [Indexed: 11/19/2022] Open
Abstract
Dendritic spines are highly dynamic neuronal compartments that control the synaptic transmission between neurons. Spines form ultrastructural units, coupling synaptic contact sites to the dendritic shaft and often harbor a spine apparatus organelle, composed of smooth endoplasmic reticulum, which is responsible for calcium sequestration and release into the spine head and neck. The spine apparatus has recently been linked to synaptic plasticity in adult human cortical neurons. While the morphological heterogeneity of spines and their intracellular organization has been extensively demonstrated in animal models, the influence of spine apparatus organelles on critical signaling pathways, such as calcium-mediated dynamics, is less well known in human dendritic spines. In this study we used serial transmission electron microscopy to anatomically reconstruct nine human cortical spines in detail as a basis for modeling and simulation of the calcium dynamics between spine and dendrite. The anatomical study of reconstructed human dendritic spines revealed that the size of the postsynaptic density correlates with spine head volume and that the spine apparatus volume is proportional to the spine volume. Using a newly developed simulation pipeline, we have linked these findings to spine-to-dendrite calcium communication. While the absence of a spine apparatus, or the presence of a purely passive spine apparatus did not enable any of the reconstructed spines to relay a calcium signal to the dendritic shaft, the calcium-induced calcium release from this intracellular organelle allowed for finely tuned “all-or-nothing” spine-to-dendrite calcium coupling; controlled by spine morphology, neck plasticity, and ryanodine receptors. Our results suggest that spine apparatus organelles are strategically positioned in the neck of human dendritic spines and demonstrate their potential relevance to the maintenance and regulation of spine-to-dendrite calcium communication. During the past decade it has become increasingly clear that abnormal synaptic plasticity is a major hallmark of neurological and cognitive disorders. Developing a better understanding of the synaptic plasticity process, which describes the ability of neurons to adapt their contacts in an activity-dependent manner, will lead to improved treatment of many neurological and cognitive disorders. It is known that calcium-dependent events such as synaptic transmission, intracellular calcium release, and calcium wave propagation, are required for many types of synaptic plasticity expression. However, the biological significance of these processes in neurons of the adult human cortex remains unknown. Due to technical limitations and ethical concerns, experimental data addressing this biologically and clinically relevant topic are not available. Therefore, we have implemented a computational model to study the intracellular calcium dynamics in realistic human dendritic spines based on detailed morphological reconstructions. With our model and simulations, we have established the morphological and biological requirements for the propagation of calcium from spines into the dendrites. Our results suggest a critical role for the calcium-storing spine apparatus organelle in regulating calcium homeostasis and propagation in human dendritic spines.
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Affiliation(s)
- James Rosado
- Department of Mathematics, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Viet Duc Bui
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Carola A. Haas
- Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Gillian Queisser
- Department of Mathematics, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (GQ); (AV)
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail: (GQ); (AV)
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23
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Otte E, Vlachos A, Asplund M. Engineering strategies towards overcoming bleeding and glial scar formation around neural probes. Cell Tissue Res 2022; 387:461-477. [PMID: 35029757 PMCID: PMC8975777 DOI: 10.1007/s00441-021-03567-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/17/2021] [Indexed: 12/15/2022]
Abstract
Neural probes are sophisticated electrophysiological tools used for intra-cortical recording and stimulation. These microelectrode arrays, designed to penetrate and interface the brain from within, contribute at the forefront of basic and clinical neuroscience. However, one of the challenges and currently most significant limitations is their ‘seamless’ long-term integration into the surrounding brain tissue. Following implantation, which is typically accompanied by bleeding, the tissue responds with a scarring process, resulting in a gliotic region closest to the probe. This glial scarring is often associated with neuroinflammation, neurodegeneration, and a leaky blood–brain interface (BBI). The engineering progress on minimizing this reaction in the form of improved materials, microfabrication, and surgical techniques is summarized in this review. As research over the past decade has progressed towards a more detailed understanding of the nature of this biological response, it is time to pose the question: Are penetrating probes completely free from glial scarring at all possible?
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24
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Neidert N, Straehle J, Erny D, Sacalean V, El Rahal A, Steybe D, Schmelzeisen R, Vlachos A, Reinacher PC, Coenen VA, Mizaikoff B, Heiland DH, Prinz M, Beck J, Schnell O. Stimulated Raman histology in the neurosurgical workflow of a major European neurosurgical center - part A. Neurosurg Rev 2021; 45:1731-1739. [PMID: 34914024 PMCID: PMC8976801 DOI: 10.1007/s10143-021-01712-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 11/26/2021] [Indexed: 12/02/2022]
Abstract
Histopathological diagnosis is the current standard for the classification of brain and spine tumors. Raman spectroscopy has been reported to allow fast and easy intraoperative tissue analysis. Here, we report data on the intraoperative implementation of a stimulated Raman histology (SRH) as an innovative strategy offering intraoperative near real-time histopathological analysis. A total of 429 SRH images from 108 patients were generated and analyzed by using a Raman imaging system (Invenio Imaging Inc.). We aimed at establishing a dedicated workflow for SRH serving as an intraoperative diagnostic, research, and quality control tool in the neurosurgical operating room (OR). First experiences with this novel imaging modality were reported and analyzed suggesting process optimization regarding tissue collection, preparation, and imaging. The Raman imaging system was rapidly integrated into the surgical workflow of a large neurosurgical center. Within a few minutes of connecting the device, the first high-quality images could be acquired in a “plug-and-play” manner. We did not encounter relevant obstacles and the learning curve was steep. However, certain prerequisites regarding quality and acquisition of tissue samples, data processing and interpretation, and high throughput adaptions must be considered. Intraoperative SRH can easily be integrated into the workflow of neurosurgical tumor resection. Considering few process optimizations that can be implemented rapidly, high-quality images can be obtained near real time. Hence, we propose SRH as a complementary tool for the diagnosis of tumor entity, analysis of tumor infiltration zones, online quality and safety control and as a research tool in the neurosurgical OR.
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Affiliation(s)
- Nicolas Neidert
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
| | - Jakob Straehle
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Daniel Erny
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Vlad Sacalean
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
| | - Amir El Rahal
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - David Steybe
- Department of Oral and Maxillofacial Surgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Rainer Schmelzeisen
- Department of Oral and Maxillofacial Surgery, Medical Center, University of Freiburg, Freiburg, Germany.,Medical Faculty, Freiburg University, Freiburg, Germany
| | - Andreas Vlachos
- Medical Faculty, Freiburg University, Freiburg, Germany.,Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Peter Christoph Reinacher
- Medical Faculty, Freiburg University, Freiburg, Germany.,Department of Stereotactic and Functional Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Fraunhofer Institute for Laser Technology (ILT), Aachen, Germany
| | - Volker Arnd Coenen
- Medical Faculty, Freiburg University, Freiburg, Germany.,Department of Stereotactic and Functional Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Boris Mizaikoff
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany.,Hahn-Schickard Institute for Microanalysis Systems, Ulm, Germany
| | - Dieter Henrik Heiland
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany.,Medical Faculty, Freiburg University, Freiburg, Germany.,Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK), partner site Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Medical Faculty, Freiburg University, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Medical Faculty, Freiburg University, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Oliver Schnell
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany. .,Medical Faculty, Freiburg University, Freiburg, Germany.
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25
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Straehle J, Erny D, Neidert N, Heiland DH, El Rahal A, Sacalean V, Steybe D, Schmelzeisen R, Vlachos A, Mizaikoff B, Reinacher PC, Coenen VA, Prinz M, Beck J, Schnell O. Neuropathological interpretation of stimulated Raman histology images of brain and spine tumors: part B. Neurosurg Rev 2021; 45:1721-1729. [PMID: 34890000 PMCID: PMC8976804 DOI: 10.1007/s10143-021-01711-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 11/26/2021] [Indexed: 12/01/2022]
Abstract
Intraoperative histopathological examinations are routinely performed to provide neurosurgeons with information about the entity of tumor tissue. Here, we quantified the neuropathological interpretability of stimulated Raman histology (SRH) acquired using a Raman laser imaging system in a routine clinical setting without any specialized training or prior experience. Stimulated Raman scattering microscopy was performed on 117 samples of pathological tissue from 73 cases of brain and spine tumor surgeries. A board-certified neuropathologist — novice in the interpretation of SRH — assessed image quality by scoring subjective tumor infiltration and stated a diagnosis based on the SRH images. The diagnostic accuracy was determined by comparison to frozen hematoxylin–eosin (H&E)-stained sections and the ground truth defined as the definitive neuropathological diagnosis. The overall SRH imaging quality was rated high with the detection of tumor cells classified as inconclusive in only 4.2% of all images. The accuracy of neuropathological diagnosis based on SRH images was 87.7% and was non-inferior to the current standard of fast frozen H&E-stained sections (87.3 vs. 88.9%, p = 0.783). We found a substantial diagnostic correlation between SRH-based neuropathological diagnosis and H&E-stained frozen sections (κ = 0.8). The interpretability of intraoperative SRH imaging was demonstrated to be equivalent to the current standard method of H&E-stained frozen sections. Further research using this label-free innovative alternative vs. conventional staining is required to determine to which extent SRH-based intraoperative decision-making can be streamlined in order to facilitate the advancement of surgical neurooncology.
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Affiliation(s)
- Jakob Straehle
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Daniel Erny
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nicolas Neidert
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
| | - Dieter Henrik Heiland
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany.,Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK), partner site Freiburg, Freiburg, Germany.,Medical Faculty of Freiburg University, Freiburg, Germany
| | - Amir El Rahal
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Vlad Sacalean
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Microenvironment and Immunology Research Laboratory, Medical Center, University of Freiburg, Freiburg, Germany
| | - David Steybe
- Department of Oral and Maxillofacial Surgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Rainer Schmelzeisen
- Medical Faculty of Freiburg University, Freiburg, Germany.,Department of Oral and Maxillofacial Surgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Medical Faculty of Freiburg University, Freiburg, Germany.,Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
| | - Boris Mizaikoff
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany.,Hahn-Schickard Institute for Microanalysis Systems, Ulm, Germany
| | - Peter Christoph Reinacher
- Medical Faculty of Freiburg University, Freiburg, Germany.,Department of Stereotactic and Functional Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Fraunhofer Institute for Laser Technology (ILT), Aachen, Germany
| | - Volker Arnd Coenen
- Medical Faculty of Freiburg University, Freiburg, Germany.,Department of Stereotactic and Functional Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Medical Faculty of Freiburg University, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.,Comprehensive Cancer Center Freiburg (CCCF), Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany.,Medical Faculty of Freiburg University, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Schnell
- Department of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany. .,Medical Faculty of Freiburg University, Freiburg, Germany.
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26
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Maoz BM, Asplund M, Maggio N, Vlachos A. Technology-based approaches toward a better understanding of neuro-coagulation in brain homeostasis. Cell Tissue Res 2021; 387:493-498. [PMID: 34850274 PMCID: PMC8975761 DOI: 10.1007/s00441-021-03560-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/12/2021] [Indexed: 12/30/2022]
Abstract
Blood coagulation factors can enter the brain under pathological conditions that affect the blood–brain interface. Besides their contribution to pathological brain states, such as neural hyperexcitability, neurodegeneration, and scar formation, coagulation factors have been linked to several physiological brain functions. It is for example well established that the coagulation factor thrombin modulates synaptic plasticity; it affects neural excitability and induces epileptic seizures via activation of protease-activated receptors in the brain. However, major limitations of current experimental and clinical approaches have prevented us from obtaining a profound mechanistic understanding of “neuro-coagulation” in health and disease. Here, we present how novel human relevant models, i.e., Organ-on-Chips equipped with advanced sensors, can help overcoming some of the limitations in the field, thus providing a perspective toward a better understanding of neuro-coagulation in brain homeostasis.
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Affiliation(s)
- Ben M Maoz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Maria Asplund
- Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany.,Division of Nursing and Medical Technology, Luleå University of Technology, Lulea, Sweden
| | - Nicola Maggio
- Department of Neurology, The Chaim Sheba Medical Center, Tel Hashomer, Israel.,Department of Neurology and Neurosurgery, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Israel
| | - Andreas Vlachos
- Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany. .,Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany. .,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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27
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Kleidonas D, Vlachos A. Scavenging Tumor Necrosis Factor α Does Not Affect Inhibition of Dentate Granule Cells Following In Vitro Entorhinal Cortex Lesion. Cells 2021; 10:3232. [PMID: 34831454 PMCID: PMC8618320 DOI: 10.3390/cells10113232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/31/2021] [Accepted: 11/16/2021] [Indexed: 11/18/2022] Open
Abstract
Neurons that lose part of their afferent input remodel their synaptic connections. While cellular and molecular mechanisms of denervation-induced changes in excitatory neurotransmission have been identified, little is known about the signaling pathways that control inhibition in denervated networks. In this study, we used mouse entorhino-hippocampal tissue cultures of both sexes to study the role of the pro-inflammatory cytokine tumor necrosis factor α (TNFα) in denervation-induced plasticity of inhibitory neurotransmission. In line with our previous findings in vitro, an entorhinal cortex lesion triggered a compensatory increase in the excitatory synaptic strength of partially denervated dentate granule cells. Inhibitory synaptic strength was not changed 3 days after the lesion. These functional changes were accompanied by a recruitment of microglia in the denervated hippocampus, and experiments in tissue cultures prepared from TNF-reporter mice [C57BL/6-Tg(TNFa-eGFP)] showed increased TNFα expression in the denervated zone. However, inhibitory neurotransmission was not affected by scavenging TNFα with a soluble TNF receptor. In turn, a decrease in inhibition, i.e., decreased frequencies of miniature inhibitory postsynaptic currents, was observed in denervated dentate granule cells of microglia-depleted tissue cultures. We conclude from these results that activated microglia maintain the inhibition of denervated dentate granule cells and that TNFα is not required for the maintenance of inhibition after denervation.
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Affiliation(s)
- Dimitrios Kleidonas
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
- Center Brain Links Brain Tools, University of Freiburg, 79110 Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
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28
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Erny D, Dokalis N, Mezö C, Castoldi A, Mossad O, Staszewski O, Frosch M, Villa M, Fuchs V, Mayer A, Neuber J, Sosat J, Tholen S, Schilling O, Vlachos A, Blank T, Gomez de Agüero M, Macpherson AJ, Pearce EJ, Prinz M. Microbiota-derived acetate enables the metabolic fitness of the brain innate immune system during health and disease. Cell Metab 2021; 33:2260-2276.e7. [PMID: 34731656 DOI: 10.1016/j.cmet.2021.10.010] [Citation(s) in RCA: 153] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/12/2021] [Accepted: 10/13/2021] [Indexed: 12/31/2022]
Abstract
As tissue macrophages of the central nervous system (CNS), microglia constitute the pivotal immune cells of this organ. Microglial features are strongly dependent on environmental cues such as commensal microbiota. Gut bacteria are known to continuously modulate microglia maturation and function by the production of short-chain fatty acids (SCFAs). However, the precise mechanism of this crosstalk is unknown. Here we determined that the immature phenotype of microglia from germ-free (GF) mice is epigenetically imprinted by H3K4me3 and H3K9ac on metabolic genes associated with substantial functional alterations including increased mitochondrial mass and specific respiratory chain dysfunctions. We identified acetate as the essential microbiome-derived SCFA driving microglia maturation and regulating the homeostatic metabolic state, and further showed that it is able to modulate microglial phagocytosis and disease progression during neurodegeneration. These findings indicate that acetate is an essential bacteria-derived molecule driving metabolic pathways and functions of microglia during health and perturbation.
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Affiliation(s)
- Daniel Erny
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nikolaos Dokalis
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Charlotte Mezö
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Angela Castoldi
- Department of Immunometabolism, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Omar Mossad
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ori Staszewski
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany
| | - Maximilian Frosch
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany
| | - Matteo Villa
- Department of Immunometabolism, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Vidmante Fuchs
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arun Mayer
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany
| | - Jana Neuber
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Janika Sosat
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Stefan Tholen
- Institute of Surgical Pathology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Oliver Schilling
- Institute of Surgical Pathology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Blank
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany
| | - Mercedes Gomez de Agüero
- Maurice E. Müller Laboratories, Department for Biomedical Research (DBMR), University Clinic of Visceral Surgery and Medicine, Inselspital, University of Bern, Bern, Switzerland
| | - Andrew J Macpherson
- Maurice E. Müller Laboratories, Department for Biomedical Research (DBMR), University Clinic of Visceral Surgery and Medicine, Inselspital, University of Bern, Bern, Switzerland
| | - Edward J Pearce
- Faculty of Biology, University of Freiburg, Freiburg, Germany; Department of Immunometabolism, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany; CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany; Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
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29
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Shirinpour S, Hananeia N, Rosado J, Tran H, Galanis C, Vlachos A, Jedlicka P, Queisser G, Opitz A. Open-source toolbox for multi-scale modeling of single neurons under transcranial magnetic stimulation. Brain Stimul 2021. [DOI: 10.1016/j.brs.2021.10.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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30
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Lenz M, Eichler A, Kruse P, Muellerleile J, Deller T, Jedlicka P, Vlachos A. All-trans retinoic acid induces synaptopodin-dependent metaplasticity in mouse dentate granule cells. eLife 2021; 10:71983. [PMID: 34723795 PMCID: PMC8560091 DOI: 10.7554/elife.71983] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/15/2021] [Indexed: 12/27/2022] Open
Abstract
Previously we showed that the vitamin A metabolite all-trans retinoic acid (atRA) induces synaptic plasticity in acute brain slices prepared from the mouse and human neocortex (Lenz et al., 2021). Depending on the brain region studied, distinct effects of atRA on excitatory and inhibitory neurotransmission have been reported. Here, we used intraperitoneal injections of atRA (10 mg/kg) in adult C57BL/6J mice to study the effects of atRA on excitatory and inhibitory neurotransmission in the mouse fascia dentata—a brain region implicated in memory acquisition. No major changes in synaptic transmission were observed in the ventral hippocampus while a significant increase in both spontaneous excitatory postsynaptic current frequencies and synapse numbers were evident in the dorsal hippocampus 6 hr after atRA administration. The intrinsic properties of hippocampal dentate granule cells were not significantly different and hippocampal transcriptome analysis revealed no essential neuronal changes upon atRA treatment. In light of these findings, we tested for the metaplastic effects of atRA, that is, for its ability to modulate synaptic plasticity expression in the absence of major changes in baseline synaptic strength. Indeed, in vivo long-term potentiation (LTP) experiments demonstrated that systemic atRA treatment improves the ability of dentate granule cells to express LTP. The plasticity-promoting effects of atRA were not observed in synaptopodin-deficient mice, therefore, extending our previous results regarding the relevance of synaptopodin in atRA-mediated synaptic strengthening in the mouse prefrontal cortex. Taken together, our data show that atRA mediates synaptopodin-dependent metaplasticity in mouse dentate granule cells.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julia Muellerleile
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany.,ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, Giessen, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
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31
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Shirinpour S, Hananeia N, Rosado J, Tran H, Galanis C, Vlachos A, Jedlicka P, Queisser G, Opitz A. Multi-scale modeling toolbox for single neuron and subcellular activity under Transcranial Magnetic Stimulation. Brain Stimul 2021; 14:1470-1482. [PMID: 34562659 PMCID: PMC8608742 DOI: 10.1016/j.brs.2021.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 09/10/2021] [Accepted: 09/15/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Transcranial Magnetic Stimulation (TMS) is a widely used non-invasive brain stimulation method. However, its mechanism of action and the neural response to TMS are still poorly understood. Multi-scale modeling can complement experimental research to study the subcellular neural effects of TMS. At the macroscopic level, sophisticated numerical models exist to estimate the induced electric fields. However, multi-scale computational modeling approaches to predict TMS cellular and subcellular responses, crucial to understanding TMS plasticity inducing protocols, are not available so far. OBJECTIVE We develop an open-source multi-scale toolbox Neuron Modeling for TMS (NeMo-TMS) to address this problem. METHODS NeMo-TMS generates accurate neuron models from morphological reconstructions, couples them to the external electric fields induced by TMS, and simulates the cellular and subcellular responses of single-pulse and repetitive TMS. RESULTS We provide examples showing some of the capabilities of the toolbox. CONCLUSION NeMo-TMS toolbox allows researchers a previously not available level of detail and precision in realistically modeling the physical and physiological effects of TMS.
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Affiliation(s)
- Sina Shirinpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA.
| | - Nicholas Hananeia
- Faculty of Medicine, ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Justus-Liebig-University, Giessen, Germany
| | - James Rosado
- Department of Mathematics, Temple University, Philadelphia, USA
| | - Harry Tran
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany; Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany; Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter Jedlicka
- Faculty of Medicine, ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Justus-Liebig-University, Giessen, Germany
| | | | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA.
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32
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Demerath T, Donkels C, Reisert M, Heers M, Rau A, Schröter N, Schulze-Bonhage A, Reinacher P, Scheiwe C, Shah MJ, Beck J, Vlachos A, Haas CA, Urbach H. Gray-White Matter Blurring of the Temporal Pole Associated With Hippocampal Sclerosis: A Microstructural Study Involving 3 T MRI and Ultrastructural Histopathology. Cereb Cortex 2021; 32:1882-1893. [PMID: 34515307 DOI: 10.1093/cercor/bhab320] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hippocampal sclerosis (HS) is often associated with gray-white matter blurring (GMB) of the anterior temporal lobe. In this study, twenty patients with unilateral temporal lobe epilepsy and HS were studied with 3 T MRI including T1 MP2RAGE and DTI/DMI sequences. Anterior temporal lobe white matter T1 relaxation times and diffusion measures were analyzed on the HS side, on the contralateral side, and in 10 normal controls. Resected brain tissue of three patients without GMB and four patients with GMB was evaluated ultrastructurally regarding axon density and diameter, the relation of the axon diameter to the total fiber diameter (G-ratio), and the thickness of the myelin sheath. Hippocampal sclerosis GMB of the anterior temporal lobe was related to prolonged T1 relaxation and axonal loss. A less pronounced reduction in axonal fraction was also found on imaging in GMB-negative temporal poles compared with normal controls. Contralateral values did not differ significantly between patients and normal controls. Reduced axonal density and axonal diameter were histopathologically confirmed in the temporopolar white matter with GMB compared to temporal poles without. These results confirm that GMB can be considered an imaging correlate for disturbed axonal maturation that can be quantified with advanced diffusion imaging.
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Affiliation(s)
- T Demerath
- Department of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
| | - C Donkels
- Department of Neurosurgery, Experimental Epilepsy Research, Medical Center-University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
| | - M Reisert
- Department of Medical Physics, Medical Center-University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany.,Deparment of Stereotactic and Functional Neurosurgery, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - M Heers
- Epilepsy Center, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - A Rau
- Department of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
| | - N Schröter
- Department of Neurology, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - A Schulze-Bonhage
- Epilepsy Center, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - P Reinacher
- Deparment of Stereotactic and Functional Neurosurgery, Medical Center-University of Freiburg, 79106 Freiburg, Germany.,Fraunhofer Institute for Laser Fraunhofer Institute for Laser Technology (ILT), Aachen, Germany
| | - C Scheiwe
- Department of Neurosurgery, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - M J Shah
- Department of Neurosurgery, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - J Beck
- Department of Neurosurgery, Medical Center-University of Freiburg, 79106 Freiburg, Germany.,Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - A Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany.,Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - C A Haas
- Department of Neurosurgery, Experimental Epilepsy Research, Medical Center-University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany.,Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - H Urbach
- Department of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
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Baasch S, Giansanti P, Kolter J, Riedl A, Forde AJ, Runge S, Zenke S, Elling R, Halenius A, Brabletz S, Hengel H, Kuster B, Brabletz T, Cicin-Sain L, Arens R, Vlachos A, Rohr JC, Stemmler MP, Kopf M, Ruzsics Z, Henneke P. Cytomegalovirus subverts macrophage identity. Cell 2021; 184:3774-3793.e25. [PMID: 34115982 DOI: 10.1016/j.cell.2021.05.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/26/2021] [Accepted: 05/07/2021] [Indexed: 12/12/2022]
Abstract
Cytomegaloviruses (CMVs) have co-evolved with their mammalian hosts for millions of years, leading to remarkable host specificity and high infection prevalence. Macrophages, which already populate barrier tissues in the embryo, are the predominant immune cells at potential CMV entry sites. Here we show that, upon CMV infection, macrophages undergo a morphological, immunophenotypic, and metabolic transformation process with features of stemness, altered migration, enhanced invasiveness, and provision of the cell cycle machinery for viral proliferation. This complex process depends on Wnt signaling and the transcription factor ZEB1. In pulmonary infection, mouse CMV primarily targets and reprograms alveolar macrophages, which alters lung physiology and facilitates primary CMV and secondary bacterial infection by attenuating the inflammatory response. Thus, CMV profoundly perturbs macrophage identity beyond established limits of plasticity and rewires specific differentiation processes, allowing viral spread and impairing innate tissue immunity.
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Affiliation(s)
- Sebastian Baasch
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Piero Giansanti
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany
| | - Julia Kolter
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - André Riedl
- Institute of Virology, University Medical Center, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Aaron James Forde
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Solveig Runge
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Simon Zenke
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Roland Elling
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Center for Pediatrics and Adolescent Medicine, University Medical Center, 79106 Freiburg, Germany
| | - Anne Halenius
- Institute of Virology, University Medical Center, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Simone Brabletz
- Department of Experimental Medicine I, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich Alexander University of Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Hartmut Hengel
- Institute of Virology, University Medical Center, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Bernhard Kuster
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany; Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), Technical University Munich, 85354 Freising, Germany
| | - Thomas Brabletz
- Department of Experimental Medicine I, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich Alexander University of Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Luka Cicin-Sain
- Immune Aging and Chronic Infections Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; Cluster of Excellence RESIST (EXC 2155), Hanover Medical School (MHH), 30625 Hanover, Germany
| | - Ramon Arens
- Department of Immunology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Jan Christopher Rohr
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Center for Pediatrics and Adolescent Medicine, University Medical Center, 79106 Freiburg, Germany
| | - Marc Philippe Stemmler
- Department of Experimental Medicine I, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich Alexander University of Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Manfred Kopf
- Institute of Molecular Health Sciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Zsolt Ruzsics
- Institute of Virology, University Medical Center, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Philipp Henneke
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), University Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Center for Pediatrics and Adolescent Medicine, University Medical Center, 79106 Freiburg, Germany.
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Turi Z, Lenz M, Paulus W, Mittner M, Vlachos A. Selecting stimulation intensity in repetitive transcranial magnetic stimulation studies: A systematic review between 1991 and 2020. Eur J Neurosci 2021; 53:3404-3415. [PMID: 33754397 DOI: 10.1111/ejn.15195] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/15/2021] [Accepted: 03/16/2021] [Indexed: 01/13/2023]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is an increasingly used, non-invasive brain stimulation technique in neuroscience research and clinical practice with a broad spectrum of suggested applications. Among other parameters, the choice of stimulus intensity and intracranial electric field strength substantially impacts rTMS outcome. This review provides a systematic overview of the intensity selection approaches and stimulation intensities used in human rTMS studies. We also examined whether studies report sufficient information to reproduce stimulus intensities for basic science research models. We performed a systematic review by focusing on original studies published between 1991 and 2020. We included conventional (e.g., 1 or 10 Hz) and patterned protocols (e.g., continuous or intermittent theta burst stimulation). We identified 3,784 articles in total, and we manually processed a representative portion (20%) of randomly selected articles. The majority of the analyzed studies (90% of entries) used the motor threshold (MT) approach and stimulation intensities from 80% to 120% of the MT. For continuous and intermittent theta burst stimulation, the most frequent stimulation intensity was 80% of the active MT. Most studies (92% of entries) did not report sufficient information to reproduce the stimulation intensity. Only a minority of studies (1.03% of entries) estimated the rTMS-induced electric field strengths. We formulate easy-to-follow recommendations to help scientists and clinicians report relevant information on stimulation intensity. Future standardized reporting guidelines may facilitate the use of basic science approaches aiming at better understanding the molecular, cellular, and neuronal mechanisms of rTMS.
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Affiliation(s)
- Zsolt Turi
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Matthias Mittner
- Department of Psychology, UiT - The Arctic University of Norway, Tromso, Norway
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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35
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Lenz M, Kruse P, Eichler A, Straehle J, Beck J, Deller T, Vlachos A. All-trans retinoic acid induces synaptic plasticity in human cortical neurons. eLife 2021; 10:e63026. [PMID: 33781382 PMCID: PMC8009674 DOI: 10.7554/elife.63026] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/11/2021] [Indexed: 12/15/2022] Open
Abstract
A defining feature of the brain is the ability of its synaptic contacts to adapt structurally and functionally in an experience-dependent manner. In the human cortex, however, direct experimental evidence for coordinated structural and functional synaptic adaptation is currently lacking. Here, we probed synaptic plasticity in human cortical slices using the vitamin A derivative all-trans retinoic acid (atRA), a putative treatment for neuropsychiatric disorders such as Alzheimer's disease. Our experiments demonstrated that the excitatory synapses of superficial (layer 2/3) pyramidal neurons underwent coordinated structural and functional changes in the presence of atRA. These synaptic adaptations were accompanied by ultrastructural remodeling of the calcium-storing spine apparatus organelle and required mRNA translation. It was not observed in synaptopodin-deficient mice, which lack spine apparatus organelles. We conclude that atRA is a potent mediator of synaptic plasticity in the adult human cortex.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
| | - Jakob Straehle
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
| | - Jürgen Beck
- Department of Neurosurgery, Medical Center and Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University FrankfurtFreiburg im BreisgauGermany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
- Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of FreiburgFreiburg im BreisgauGermany
- Center Brain Links Brain Tools, University of FreiburgFreiburg im BreisgauGermany
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36
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Turi Z, Normann C, Domschke K, Vlachos A. Transcranial Magnetic Stimulation in Psychiatry: Is There a Need for Electric Field Standardization? Front Hum Neurosci 2021; 15:639640. [PMID: 33767616 PMCID: PMC7985083 DOI: 10.3389/fnhum.2021.639640] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/16/2021] [Indexed: 01/29/2023] Open
Abstract
Single-pulse and repetitive transcranial magnetic stimulation (rTMS) are used in clinical practice for diagnostic and therapeutic purposes. However, rTMS-based therapies that lead to a significant and sustained reduction in neuropsychiatric symptoms remain scarce. While it is generally accepted that the stimulation frequency plays a crucial role in producing the therapeutic effects of rTMS, less attention has been dedicated to determining the role of the electric field strength. Conventional threshold-based intensity selection approaches, such as the resting motor threshold, produce variable stimulation intensities and electric fields across participants and cortical regions. Insufficient standardization of electric field strength may contribute to the variability of rTMS effects and thus therapeutic success. Computational approaches that can prospectively optimize the electric field and standardize it across patients and cortical targets may overcome some of these limitations. Here, we discuss these approaches and propose that electric field standardization will be instrumental for translational science frameworks (e.g., multiscale modeling and basic science approaches) aimed at deciphering the subcellular, cellular, and network mechanisms of rTMS. Advances in understanding these mechanisms will be important for optimizing rTMS-based therapies in psychiatry.
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Affiliation(s)
- Zsolt Turi
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Claus Normann
- Department of Psychiatry and Psychotherapy, Medical Center—Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center—Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
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Hildebrandt-Einfeldt L, Yap K, Paul MH, Stoffer C, Zahn N, Drakew A, Lenz M, Vlachos A, Deller T. Crossed Entorhino-Dentate Projections Form and Terminate With Correct Layer-Specificity in Organotypic Slice Cultures of the Mouse Hippocampus. Front Neuroanat 2021; 15:637036. [PMID: 33643001 PMCID: PMC7904698 DOI: 10.3389/fnana.2021.637036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/12/2021] [Indexed: 11/13/2022] Open
Abstract
The entorhino-dentate projection, i.e., the perforant pathway, terminates in a highly ordered and laminated fashion in the rodent dentate gyrus (DG): fibers arising from the medial entorhinal cortex (MEC) terminate in the middle molecular layer, whereas fibers arising from the lateral entorhinal cortex (LEC) terminate in the outer molecular layer of the DG. In rats and rabbits, a crossed entorhino-dentate projection exists, which originates from the entorhinal cortex (EC) and terminates in the contralateral DG. In contrast, in mice, such a crossed projection is reportedly absent. Using single and double mouse organotypic entorhino-hippocampal slice cultures, we studied the ipsi- and crossed entorhino-dentate projections. Viral tracing revealed that entorhino-dentate projections terminate with a high degree of lamina-specificity in single as well as in double cultures. Furthermore, in double cultures, entorhinal axons arising from one slice freely intermingled with entorhinal axons originating from the other slice. In single as well as in double cultures, entorhinal axons exhibited a correct topographical projection to the DG: medial entorhinal axons terminated in the middle and lateral entorhinal axons terminated in the outer molecular layer. Finally, entorhinal neurons were virally transduced with Channelrhodopsin2-YFP and stimulated with light, revealing functional connections between the EC and dentate granule cells. We conclude from our findings that entorhino-dentate projections form bilaterally in the mouse hippocampus in vitro and that the mouse DG provides a permissive environment for crossed entorhinal fibers.
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Affiliation(s)
- Lars Hildebrandt-Einfeldt
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Kenrick Yap
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Mandy H Paul
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Carolin Stoffer
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Nadine Zahn
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Alexander Drakew
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuro Modulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
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Lenz M, Eichler A, Kruse P, Strehl A, Rodriguez-Rozada S, Goren I, Yogev N, Frank S, Waisman A, Deller T, Jung S, Maggio N, Vlachos A. Interleukin 10 Restores Lipopolysaccharide-Induced Alterations in Synaptic Plasticity Probed by Repetitive Magnetic Stimulation. Front Immunol 2020; 11:614509. [PMID: 33391287 PMCID: PMC7772211 DOI: 10.3389/fimmu.2020.614509] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022] Open
Abstract
Systemic inflammation is associated with alterations in complex brain functions such as learning and memory. However, diagnostic approaches to functionally assess and quantify inflammation-associated alterations in synaptic plasticity are not well-established. In previous work, we demonstrated that bacterial lipopolysaccharide (LPS)-induced systemic inflammation alters the ability of hippocampal neurons to express synaptic plasticity, i.e., the long-term potentiation (LTP) of excitatory neurotransmission. Here, we tested whether synaptic plasticity induced by repetitive magnetic stimulation (rMS), a non-invasive brain stimulation technique used in clinical practice, is affected by LPS-induced inflammation. Specifically, we explored brain tissue cultures to learn more about the direct effects of LPS on neural tissue, and we tested for the plasticity-restoring effects of the anti-inflammatory cytokine interleukin 10 (IL10). As shown previously, 10 Hz repetitive magnetic stimulation (rMS) of organotypic entorhino-hippocampal tissue cultures induced a robust increase in excitatory neurotransmission onto CA1 pyramidal neurons. Furthermore, LPS-treated tissue cultures did not express rMS-induced synaptic plasticity. Live-cell microscopy in tissue cultures prepared from a novel transgenic reporter mouse line [C57BL/6-Tg(TNFa-eGFP)] confirms that ex vivo LPS administration triggers microglial tumor necrosis factor alpha (TNFα) expression, which is ameliorated in the presence of IL10. Consistent with this observation, IL10 hampers the LPS-induced increase in TNFα, IL6, IL1β, and IFNγ and restores the ability of neurons to express rMS-induced synaptic plasticity in the presence of LPS. These findings establish organotypic tissue cultures as a suitable model for studying inflammation-induced alterations in synaptic plasticity, thus providing a biological basis for the diagnostic use of transcranial magnetic stimulation in the context of brain inflammation.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Strehl
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Silvia Rodriguez-Rozada
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Itamar Goren
- Pharmazentrum Frankfurt/ZAFES, Goethe-University Frankfurt, Frankfurt, Germany
| | - Nir Yogev
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Department of Dermatology, Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Stefan Frank
- Pharmazentrum Frankfurt/ZAFES, Goethe-University Frankfurt, Frankfurt, Germany
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Steffen Jung
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Nicola Maggio
- Department of Neurology and Sagol Center for Neurosciences, Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Tel HaShomer, Israel
- Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Hille L, Lenz M, Vlachos A, Grüning B, Hein L, Neumann FJ, Nührenberg TG, Trenk D. Ultrastructural, transcriptional, and functional differences between human reticulated and non-reticulated platelets. J Thromb Haemost 2020; 18:2034-2046. [PMID: 32428354 DOI: 10.1111/jth.14895] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/22/2020] [Accepted: 05/06/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Reticulated platelets (RP) are the youngest circulating platelets in blood. An increased amount of this subpopulation is associated with higher cardiovascular risk and mortality. OBJECTIVES It is unknown to what extent intrinsic properties of RP contribute to their hyperreactive features. This study is the first providing a multifactorial approach based on ultrastructural, transcriptional, and functional analysis of RP compared to non-RP sorted by flow cytometry. METHODS Reticulated platelets and non-RP were sorted after platelet staining with SYTO 13. Employing transmission electron microscopy, 1089 micrographs were analyzed for platelet size, amounts of intracellular structures, and anatomical surrogates indicating activation. Long and small RNA-sequencing (RNA-seq) were performed for analyzing differential gene expression. Functional analysis of P-selectin-an upregulated mRNA in RP-was performed in healthy subjects and patients on P2Y12 -inhibitors. RESULTS Electron micrographs uncovered distinct ultrastructural differences in RP versus non-RP. Cross sections were 1.9-fold larger in RP (P < .0001). Amounts of α-granules, dense granules, open canalicular system-openings, and mitochondria were increased in RP, which persisted after adjustment for platelet size. Long RNA-seq showed 1212 upregulated transcripts that are predominantly associated to platelet shape change, aggregation, and activation; 1264 mRNAs were downregulated in RP. Small RNA-seq did not reveal any differentially expressed transcripts. Functional analysis displayed higher P-selectin expression as compared to non-RP upon ADP- or TRAP-stimulation. CONCLUSIONS Our results demonstrate that altered intrinsic structural and molecular properties contribute to the hyperreactivity of RP. These properties and an increased amount of RP may account for the association with cardiovascular risk.
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Affiliation(s)
- Laura Hille
- Department of Cardiology and Angiology II, Clinical Pharmacology, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation, University of Freiburg, Freiburg, Germany
| | - Björn Grüning
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Lutz Hein
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Franz-Josef Neumann
- Department of Cardiology and Angiology II, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| | - Thomas G Nührenberg
- Department of Cardiology and Angiology II, Clinical Pharmacology, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
- Department of Cardiology and Angiology II, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| | - Dietmar Trenk
- Department of Cardiology and Angiology II, Clinical Pharmacology, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
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40
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Masuda T, Amann L, Sankowski R, Staszewski O, Lenz M, D Errico P, Snaidero N, Costa Jordão MJ, Böttcher C, Kierdorf K, Jung S, Priller J, Misgeld T, Vlachos A, Meyer-Luehmann M, Knobeloch KP, Prinz M. Novel Hexb-based tools for studying microglia in the CNS. Nat Immunol 2020; 21:802-815. [PMID: 32541832 DOI: 10.1038/s41590-020-0707-4] [Citation(s) in RCA: 159] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 05/07/2020] [Indexed: 12/26/2022]
Abstract
Microglia and central nervous system (CNS)-associated macrophages (CAMs), such as perivascular and meningeal macrophages, are implicated in virtually all diseases of the CNS. However, little is known about their cell-type-specific roles in the absence of suitable tools that would allow for functional discrimination between the ontogenetically closely related microglia and CAMs. To develop a new microglia gene targeting model, we first applied massively parallel single-cell analyses to compare microglia and CAM signatures during homeostasis and disease and identified hexosaminidase subunit beta (Hexb) as a stably expressed microglia core gene, whereas other microglia core genes were substantially downregulated during pathologies. Next, we generated HexbtdTomato mice to stably monitor microglia behavior in vivo. Finally, the Hexb locus was employed for tamoxifen-inducible Cre-mediated gene manipulation in microglia and for fate mapping of microglia but not CAMs. In sum, we provide valuable new genetic tools to specifically study microglia functions in the CNS.
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Affiliation(s)
- Takahiro Masuda
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
| | - Lukas Amann
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Roman Sankowski
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Berta-Ottenstein-Programme for Clinician Scientists, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ori Staszewski
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Berta-Ottenstein-Programme for Clinician Scientists, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Paolo D Errico
- Department of Neurology, Medical Center-University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | | | - Chotima Böttcher
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Katrin Kierdorf
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Steffen Jung
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Josef Priller
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry, Charité-Universitätsmedizin Berlin, Berlin, Germany
- DZNE and BIH, Berlin, Germany
- University of Edinburgh and UK DRI, Edinburgh, UK
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Melanie Meyer-Luehmann
- Department of Neurology, Medical Center-University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Klaus-Peter Knobeloch
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
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Novitskaya Y, Dümpelmann M, Vlachos A, Reinacher PC, Schulze-Bonhage A. In vivo-assessment of the human temporal network: Evidence for asymmetrical effective connectivity. Neuroimage 2020; 214:116769. [PMID: 32217164 DOI: 10.1016/j.neuroimage.2020.116769] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/22/2020] [Accepted: 03/19/2020] [Indexed: 11/16/2022] Open
Abstract
The human temporal lobe is a multimodal association area which plays a key role in various aspects of cognition, particularly in memory formation and spatial navigation. Functional and anatomical connectivity of temporal structures is thus a subject of intense research, yet by far underexplored in humans due to ethical and technical limitations. We assessed intratemporal cortico-cortical interactions in the living human brain by means of single pulse electrical stimulation, an invasive method allowing mapping effective intracortical connectivity with a high spatiotemporal resolution. Eighteen subjects with normal anterior-mesial temporal MR imaging undergoing intracranial presurgical epilepsy diagnostics with multiple depth electrodes were included. The investigated structures were temporal pole, hippocampus, amygdala and parahippocampal gyrus. Intratemporal cortical connectivity was assessed as a function of amplitude of the early component of the cortico-cortical evoked potentials (CCEP). While the analysis revealed robust interconnectivity between all explored structures, a clear asymmetry in bidirectional connectivity was detected for the hippocampal network and for the connections between the temporal pole and parahippocampal gyrus. The amygdala showed bidirectional asymmetry only to the hippocampus. The provided evidence of asymmetrically weighed intratemporal effective connectivity in humans in vivo is important for understanding of functional interactions within the temporal lobe since asymmetries in the brain connectivity define hierarchies in information processing. The findings are in exact accord with the anatomical tracing studies in non-human primates and open a translational route for interventions employing modulation of temporal lobe function.
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Affiliation(s)
- Yulia Novitskaya
- Epilepsy Center, Department of Neurosurgery, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany.
| | - Matthias Dümpelmann
- Epilepsy Center, Department of Neurosurgery, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albert Strasse 17, 79104, Freiburg, Germany; Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany
| | - Peter Christoph Reinacher
- Department of Stereotactic and Functional Neurosurgery, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Department of Neurosurgery, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany; Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany
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42
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Galanis C, Vlachos A. Hebbian and Homeostatic Synaptic Plasticity-Do Alterations of One Reflect Enhancement of the Other? Front Cell Neurosci 2020; 14:50. [PMID: 32256317 PMCID: PMC7093376 DOI: 10.3389/fncel.2020.00050] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/21/2020] [Indexed: 01/07/2023] Open
Abstract
During the past 50 years, the cellular and molecular mechanisms of synaptic plasticity have been studied in great detail. A plethora of signaling pathways have been identified that account for synaptic changes based on positive and negative feedback mechanisms. Yet, the biological significance of Hebbian synaptic plasticity (= positive feedback) and homeostatic synaptic plasticity (= negative feedback) remains a matter of debate. Specifically, it is unclear how these opposing forms of plasticity, which share common downstream mechanisms, operate in the same networks, neurons, and synapses. Based on the observation that rapid and input-specific homeostatic mechanisms exist, we here discuss a model that is based on signaling pathways that may adjust a balance between Hebbian and homeostatic synaptic plasticity. Hence, “alterations” in Hebbian plasticity may, in fact, resemble “enhanced” homeostasis, which rapidly returns synaptic strength to baseline. In turn, long-lasting experience-dependent synaptic changes may require attenuation of homeostatic mechanisms or the adjustment of homeostatic setpoints at the single-synapse level. In this context, we propose a role for the proteolytic processing of the amyloid precursor protein (APP) in setting a balance between the ability of neurons to express Hebbian and homeostatic synaptic plasticity.
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Affiliation(s)
- Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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43
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Rudan Njavro J, Klotz J, Dislich B, Wanngren J, Shmueli MD, Herber J, Kuhn PH, Kumar R, Koeglsperger T, Conrad M, Wurst W, Feederle R, Vlachos A, Michalakis S, Jedlicka P, Müller SA, Lichtenthaler SF. Mouse brain proteomics establishes MDGA1 and CACHD1 as in vivo substrates of the Alzheimer protease BACE1. FASEB J 2019; 34:2465-2482. [PMID: 31908000 DOI: 10.1096/fj.201902347r] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/22/2019] [Accepted: 12/03/2019] [Indexed: 01/18/2023]
Abstract
The protease beta-site APP cleaving enzyme 1 (BACE1) has fundamental functions in the nervous system. Its inhibition is a major therapeutic approach in Alzheimer's disease, because BACE1 cleaves the amyloid precursor protein (APP), thereby catalyzing the first step in the generation of the pathogenic amyloid beta (Aβ) peptide. Yet, BACE1 cleaves numerous additional membrane proteins besides APP. Most of these substrates have been identified in vitro, but only few were further validated or characterized in vivo. To identify BACE1 substrates with in vivo relevance, we used isotope label-based quantitative proteomics of wild type and BACE1-deficient (BACE1 KO) mouse brains. This approach identified known BACE1 substrates, including Close homolog of L1 and contactin-2, which were found to be enriched in the membrane fraction of BACE1 KO brains. VWFA and cache domain-containing protein 1 (CACHD)1 and MAM domain-containing glycosylphosphatidylinositol anchor protein 1 (MDGA1), which have functions in synaptic transmission, were identified and validated as new BACE1 substrates in vivo by immunoblots using primary neurons and mouse brains. Inhibition or deletion of BACE1 from primary neurons resulted in a pronounced inhibition of substrate cleavage and a concomitant increase in full-length protein levels of CACHD1 and MDGA1. The BACE1 cleavage site in both proteins was determined to be located within the juxtamembrane domain. In summary, this study identifies and validates CACHD1 and MDGA1 as novel in vivo substrates for BACE1, suggesting that cleavage of both proteins may contribute to the numerous functions of BACE1 in the nervous system.
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Affiliation(s)
- Jasenka Rudan Njavro
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jakob Klotz
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Bastian Dislich
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute of Pathology, University of Bern, Switzerland
| | - Johanna Wanngren
- Division of Neurogeriatrics, Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Merav D Shmueli
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
| | - Julia Herber
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Peer-Hendrik Kuhn
- Institute of Pathology, Technical University of Munich, Munich, Germany
| | - Rohit Kumar
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Neurology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Thomas Koeglsperger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Marcus Conrad
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Genome Engineering, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Developmental Genetics, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Regina Feederle
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Research Center for Environmental Health, Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Helmholtz Zentrum München, Neuherberg, Germany.,Core Facility Monoclonal Antibodies, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Germany.,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Germany
| | - Stylianos Michalakis
- Department of Ophthalmology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Peter Jedlicka
- Faculty of Medicine, ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Justus-Liebig-University, Giessen, Germany.,Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe University, Frankfurt am Main, Germany.,Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany
| | - Stephan A Müller
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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Donkels C, Peters M, Fariña Núñez MT, Nakagawa JM, Kirsch M, Vlachos A, Scheiwe C, Schulze-Bonhage A, Prinz M, Beck J, Haas CA. Oligodendrocyte lineage and myelination are compromised in the gray matter of focal cortical dysplasia type IIa. Epilepsia 2019; 61:171-184. [PMID: 31872870 DOI: 10.1111/epi.16415] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/28/2019] [Accepted: 11/29/2019] [Indexed: 01/26/2023]
Abstract
OBJECTIVES Focal cortical dysplasias (FCDs) are local malformations of the human neocortex and a leading cause of medically intractable epilepsy. FCDs are characterized by local architectural disturbances of the neocortex and often by a blurred gray-white matter boundary indicating abnormal white matter myelination. We have recently shown that myelination is also compromised in the gray matter of dysplastic areas, since transcripts encoding factors for oligodendrocyte differentiation and myelination are downregulated and myelin fibers appear fractured and disorganized. METHODS Here, we characterized the gray matter-associated myelination pathology in detail by in situ hybridization, immunohistochemistry, and electron microscopy with markers for myelin, mature oligodendrocytes, and oligodendrocyte precursor cells in tissue sections of FCD IIa and control cortices. In addition, we isolated oligodendrocyte precursor cells from resected dysplastic tissue and performed proliferation assays. RESULTS We show that the proportion of myelinated gray matter is similar in the dysplastic cortex to that in controls and myelinated fibers extend up to layer III. On the ultrastructural level, however, we found that the myelin sheaths of layer V axons are thinner in dysplastic specimens than in controls. In addition, the density of oligodendrocyte precursor cells and of mature oligodendrocytes was reduced. Finally, we show for the first time that oligodendrocyte precursor cells isolated from resected dysplastic cortex have a reduced proliferation capacity in comparison to controls. SIGNIFICANCE These results indicate that proliferation and differentiation of oligodendrocyte precursor cells and the formation of myelin sheaths are compromised in FCD and might contribute to the epileptogenicity of this cortical malformation.
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Affiliation(s)
- Catharina Donkels
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Myriam Peters
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Mateo T Fariña Núñez
- Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julia M Nakagawa
- Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Kirsch
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christian Scheiwe
- Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Schulze-Bonhage
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Epilepsy Center Freiburg, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools, Cluster of Excellence, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Signalling Research Centers BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools, Cluster of Excellence, University of Freiburg, Freiburg, Germany
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Lenz M, Shimon MB, Benninger F, Neufeld MY, Shavit-Stein E, Vlachos A, Maggio N. Systemic thrombin inhibition ameliorates seizures in a mouse model of pilocarpine-induced status epilepticus. J Mol Med (Berl) 2019; 97:1567-1574. [PMID: 31667526 DOI: 10.1007/s00109-019-01837-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 09/10/2019] [Accepted: 09/20/2019] [Indexed: 10/25/2022]
Abstract
Status epilepticus (SE) is a life-threatening condition characterized by ongoing seizure activity which can lead to severe brain damage and death if not treated properly. Recent work suggests that alterations in blood-brain barrier (BBB) function and subsequent cortical exposure to coagulation factors may initiate, promote, and/or sustain SE. This suggestion is based on the observation that the serine protease thrombin, which plays a fundamental role in the blood coagulation cascade, increases neural excitability through the activation of protease-activated receptor 1 (PAR1). However, it remains unclear whether systemic inhibition of thrombin asserts "anti-epileptic" effects in vivo. We here used the pilocarpine model of SE in adult 3-month-old male mice to address the question whether intraperitoneal injection of the thrombin inhibitor α-NAPAP (0.75 mg/kg) counters SE. Indeed, pharmacological inhibition of thrombin ameliorates the behavioral outcome of pilocarpine-induced SE. Similar results are obtained when the thrombin receptor PAR1 is pharmacologically blocked using intraperitoneal injection of SCH79797 (25 μg/kg) prior to SE induction. Consistent with these results, an increase in thrombin immunofluorescence is detected in the hippocampus of pilocarpine-treated animals. Moreover, increased hippocampal serine protease activity is detected 90 min after SE induction, which is not observed in animals treated with α-NAPAP prior to SE induction. Together, these results corroborate and extend recent studies suggesting that novel oral anticoagulants which target thrombin (and PAR1) may assert anti-epileptic effects in vivo. KEY MESSAGES: Systemic thrombin/PAR1-inhibition ameliorates anticoagulants behavioral seizures. Status epilepticus increases thrombin levels in the hippocampus. Increased serine protease activity in the hippocampus after status epileptic. Anti-epileptic potential of clinically used anticoagulants must be evaluated.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Marina Ben Shimon
- Department of Neurology, The Chaim Sheba Medical Center, Tel HaShomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Felix Benninger
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Neurology, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Miri Y Neufeld
- Department of Neurology, The Chaim Sheba Medical Center, Tel HaShomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Efrat Shavit-Stein
- Department of Neurology, The Chaim Sheba Medical Center, Tel HaShomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany. .,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany.
| | - Nicola Maggio
- Department of Neurology, The Chaim Sheba Medical Center, Tel HaShomer, Israel. .,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. .,Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Tel HaShomer, Israel. .,Department of Neurology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. .,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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46
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Hille L, Nuehrenberg T, Lenz M, Vlachos A, Trenk D. P3502Transmission electron microscopy reveals ultrastructural differences between reticulated and non-reticulated human platelets. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.0367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Reticulated platelets (RP) are the youngest circulating platelets in blood. Compared to older platelets, RP represent a highly active prothrombotic platelet population associated with an increased risk for cardiovascular events, mortality and impaired response to antiplatelet drugs compared to older platelets (non-RP). The underlying mechanisms for these characteristics of RP are so far poorly understood.
This study aimed to characterize ultrastructural properties of RP and non-RP by transmission electron microscopy (TEM) of FACS-sorted human platelets using a novel staining method for RP.
Washed platelets from three healthy donors were stained by SYTO™13, a nucleic acid binding fluorescent dye, which enables determination of RP and non-RP based on their RNA-content. 8×106 platelets were fixed, sorted and sandwiched between two layers of agarose gel. Samples were further processed for visualization by TEM. In total, 1047 platelets, i.e., electron micrographs of individual cross-sections, were analysed by an investigator blinded concerning experimental condition. Sizes, numbers of α-granules, dense granules, mitochondria and open canalicular system openings were assessed in RP and non-RP, respectively. Furthermore, platelets were screened for pseudopodia formation as an indicator for activation.
Cross-sectional area was significantly different between RP and non-RP (2.44 [1.80–3.22] vs. 1.34 [1.04–1.89] μm2; p<0.0001; median with IQR). α-granule and mitochondria amounts were higher in RP which persisted even after adjustment for platelet size (α-granules: 4.64 [3.46–5.86]/μm2 vs. 4.15 [2.87–5.26]/μm2; p<0.0001; mitochondria: 0.33±0.02 /μm2 vs. 0.12±0.01/μm2; mean ± SEM). In contrast, the amount of open canalicular system openings per square μm was higher in the non-RP group (5.82 [4.34–7.68] /μm2 vs. 5.52 [4.01–7.11] /μm2; p=0.009). Dense granule content per square μm was similar in both RP and non-RP. Pseudopodia were present in 38% (RP) respective 37% (non-RP) of platelets. Notably, golgi apparatus and rough endoplasmic reticulum which are rarely seen in platelets were detected in several RP.
Analysis of TEM pictures revealed an almost 2-fold higher cross-sectional area in RP compared to non-RP. Even after adjustment for differences in size, α-granule content remained significantly higher in RP indicating a higher storage pool for prothrombotic constituents like p-selectin or von Willebrand factor. Although the relative amount of dense granules per area did not differ between the two groups, a higher absolute number of dense granules per platelet in the RP group is indicative for higher amounts of stored small molecules such as ADP, calcium or serotonin. Despite the anucleate nature of platelets, the presence of golgi apparatus and rough endoplasmic reticulum suggests the capability of protein biosynthesis in RP. These comprehensive findings provide new important insight into the ultrastructural properties of human RP.
Acknowledgement/Funding
PharmCompNet Baden-Württemberg: Kompetenznetzwerk Pharmakologie Baden-Württemberg
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Affiliation(s)
- L Hille
- University Heart Center Freiburg-Bad Krozingen, Department of Clinical Pharmacology, Bad Krozingen, Germany
| | - T Nuehrenberg
- University Heart Center Freiburg-Bad Krozingen, Department of Clinical Pharmacology, Bad Krozingen, Germany
| | - M Lenz
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Department of Neuroanatomy, Freiburg, Germany
| | - A Vlachos
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Department of Neuroanatomy, Freiburg, Germany
| | - D Trenk
- University Heart Center Freiburg-Bad Krozingen, Department of Clinical Pharmacology, Bad Krozingen, Germany
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Galanis C, Lenz M, Opitz A, Vlachos A. P19 Repetitive magnetic stimulation of mouse and rat hippocampal tissue cultures reveals distinct stimulation intensity thresholds for the induction of excitatory synaptic plasticity. Clin Neurophysiol 2019. [DOI: 10.1016/j.clinph.2019.04.673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Lenz M, Galanis C, Kleidonas D, Fellenz M, Deller T, Vlachos A. Denervated mouse dentate granule cells adjust their excitatory but not inhibitory synapses following in vitro entorhinal cortex lesion. Exp Neurol 2018; 312:1-9. [PMID: 30401642 DOI: 10.1016/j.expneurol.2018.10.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/16/2018] [Accepted: 10/23/2018] [Indexed: 01/04/2023]
Abstract
Neurons adjust their synaptic strength in a homeostatic manner following changes in network activity and connectivity. While this form of plasticity has been studied in detail for excitatory synapses, homeostatic plasticity of inhibitory synapses remains not well-understood. In the present study, we employed entorhinal cortex lesion (ECL) of organotypic entorhino-hippocampal tissue cultures to test for homeostatic changes in GABAergic neurotransmission onto partially denervated dentate granule cells. Using single and paired whole-cell patch-clamp recordings, as well as immunostainings for synaptic markers, we find that excitatory synaptic strength is robustly increased 3 days post lesion (dpl), whereas GABAergic neurotransmission is not changed after denervation. Even under conditions of pharmacological inhibition of glutamatergic neurotransmission, which prevents neurons to compensate for the loss of input via excitatory synaptic scaling, down-scaling of GABAergic synapses does not emerge 3 days after denervation. We conclude that granule cells maintain structural and functional properties of GABAergic synapses even in the face of substantial changes in network connectivity. Hence, alterations in inhibitory neurotransmission, as seen in pathological brain states, may not simply reflect a homeostatic response to disconnection.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany; Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt 60590, Germany
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany
| | - Dimitrios Kleidonas
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany
| | - Meike Fellenz
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt 60590, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt 60590, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany.
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49
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Breit M, Kessler M, Stepniewski M, Vlachos A, Queisser G. Spine-to-Dendrite Calcium Modeling Discloses Relevance for Precise Positioning of Ryanodine Receptor-Containing Spine Endoplasmic Reticulum. Sci Rep 2018; 8:15624. [PMID: 30353066 PMCID: PMC6199256 DOI: 10.1038/s41598-018-33343-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 09/18/2018] [Indexed: 12/15/2022] Open
Abstract
The endoplasmic reticulum (ER) forms a complex endomembrane network that reaches into the cellular compartments of a neuron, including dendritic spines. Recent work discloses that the spine ER is a dynamic structure that enters and leaves spines. While evidence exists that ER Ca2+ release is involved in synaptic plasticity, the role of spine ER morphology remains unknown. Combining a new 3D spine generator with 3D Ca2+ modeling, we addressed the relevance of ER positioning on spine-to-dendrite Ca2+ signaling. Our simulations, which account for Ca2+ exchange on the plasma membrane and ER, show that spine ER needs to be present in distinct morphological conformations in order to overcome a barrier between the spine and dendritic shaft. We demonstrate that RyR-carrying spine ER promotes spine-to-dendrite Ca2+ signals in a position-dependent manner. Our simulations indicate that RyR-carrying ER can initiate time-delayed Ca2+ reverberation, depending on the precise position of the spine ER. Upon spine growth, structural reorganization of the ER restores spine-to-dendrite Ca2+ communication, while maintaining aspects of Ca2+ homeostasis in the spine head. Our work emphasizes the relevance of precise positioning of RyR-containing spine ER in regulating the strength and timing of spine Ca2+ signaling, which could play an important role in tuning spine-to-dendrite Ca2+ communication and homeostasis.
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Affiliation(s)
- Markus Breit
- Goethe Center for Scientific Computing, Computational Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Marcus Kessler
- Goethe Center for Scientific Computing, Computational Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Martin Stepniewski
- Goethe Center for Scientific Computing, Computational Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, 79104, Germany. .,Bernstein Center Freiburg, University of Freiburg, Freiburg, 79104, Germany.
| | - Gillian Queisser
- Department of Mathematics, Temple University, Philadelphia, USA.
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Strehl A, Galanis C, Radic T, Schwarzacher SW, Deller T, Vlachos A. Dopamine Modulates Homeostatic Excitatory Synaptic Plasticity of Immature Dentate Granule Cells in Entorhino-Hippocampal Slice Cultures. Front Mol Neurosci 2018; 11:303. [PMID: 30214394 PMCID: PMC6125303 DOI: 10.3389/fnmol.2018.00303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/09/2018] [Indexed: 01/27/2023] Open
Abstract
Homeostatic plasticity mechanisms maintain neurons in a stable state. To what extent these mechanisms are relevant during the structural and functional maturation of neural tissue is poorly understood. To reveal developmental changes of a major homeostatic plasticity mechanism, i.e., homeostatic excitatory synaptic plasticity, we analyzed 1-week- and 4-week-old entorhino-hippocampal slice cultures and investigated the ability of immature and mature dentate granule cells (GCs) to express this form of plasticity. Our experiments demonstrate that immature GCs are capable of adjusting their excitatory synaptic strength in a compensatory manner at early postnatal stages, i.e., in 1-week-old preparations, as is the case for mature GCs. This ability of immature dentate GCs is absent in 4-week-old slice cultures. Further investigations into the signaling pathways reveal an important role of dopamine (DA), which prevents homeostatic synaptic up-scaling of immature GCs in young cultures, whereas it does not affect immature and mature GCs in 4-week-old preparations. Together, these results disclose the ability of immature GCs to express homeostatic synaptic plasticity during early postnatal development. They hint toward a novel role of dopaminergic signaling, which may gate activity-dependent changes of newly born neurons by blocking homeostasis.
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Affiliation(s)
- Andreas Strehl
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tijana Radic
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | | | - Thomas Deller
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | - Andreas Vlachos
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany.,Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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