1
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Bagheri H, Friedman H, Hadwen A, Jarweh C, Cooper E, Oprea L, Guerrier C, Khadra A, Collin A, Cohen-Adad J, Young A, Victoriano GM, Swire M, Jarjour A, Bechler ME, Pryce RS, Chaurand P, Cougnaud L, Vuckovic D, Wilion E, Greene O, Nishiyama A, Benmamar-Badel A, Owens T, Grouza V, Tuznik M, Liu H, Rudko DA, Zhang J, Siminovitch KA, Peterson AC. Myelin basic protein mRNA levels affect myelin sheath dimensions, architecture, plasticity, and density of resident glial cells. Glia 2024; 72:1893-1914. [PMID: 39023138 DOI: 10.1002/glia.24589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 05/29/2024] [Accepted: 06/23/2024] [Indexed: 07/20/2024]
Abstract
Myelin Basic Protein (MBP) is essential for both elaboration and maintenance of CNS myelin, and its reduced accumulation results in hypomyelination. How different Mbp mRNA levels affect myelin dimensions across the lifespan and how resident glial cells may respond to such changes are unknown. Here, to investigate these questions, we used enhancer-edited mouse lines that accumulate Mbp mRNA levels ranging from 8% to 160% of wild type. In young mice, reduced Mbp mRNA levels resulted in corresponding decreases in Mbp protein accumulation and myelin sheath thickness, confirming the previously demonstrated rate-limiting role of Mbp transcription in the control of initial myelin synthesis. However, despite maintaining lower line specific Mbp mRNA levels into old age, both MBP protein levels and myelin thickness improved or fully normalized at rates defined by the relative Mbp mRNA level. Sheath length, in contrast, was affected only when mRNA levels were very low, demonstrating that sheath thickness and length are not equally coupled to Mbp mRNA level. Striking abnormalities in sheath structure also emerged with reduced mRNA levels. Unexpectedly, an increase in the density of all glial cell types arose in response to reduced Mbp mRNA levels. This investigation extends understanding of the role MBP plays in myelin sheath elaboration, architecture, and plasticity across the mouse lifespan and illuminates a novel axis of glial cell crosstalk.
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Affiliation(s)
- Hooman Bagheri
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Hana Friedman
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Amanda Hadwen
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Celia Jarweh
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Ellis Cooper
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Lawrence Oprea
- Integrated Program in Neuroscience, McGill University, Montréal, Quebec, Canada
| | | | - Anmar Khadra
- Integrated Program in Neuroscience, McGill University, Montréal, Quebec, Canada
| | - Armand Collin
- Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada
| | - Julien Cohen-Adad
- Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada
| | - Amanda Young
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Gerardo Mendez Victoriano
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Matthew Swire
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Andrew Jarjour
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Marie E Bechler
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Rachel S Pryce
- Department of Chemistry, Université de Montréal, Montreal, Quebec, Canada
| | - Pierre Chaurand
- Department of Chemistry, Université de Montréal, Montreal, Quebec, Canada
| | - Lise Cougnaud
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Quebec, Canada
| | - Dajana Vuckovic
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Quebec, Canada
| | - Elliott Wilion
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, USA
| | - Owen Greene
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, USA
| | - Akiko Nishiyama
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, USA
- The Connecticut Institute for Brain and Cognitive Sciences, University of Connecticut, Storrs, Connecticut, USA
| | - Anouk Benmamar-Badel
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Trevor Owens
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Vladimir Grouza
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Marius Tuznik
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Hanwen Liu
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - David A Rudko
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Jinyi Zhang
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Mount Sinai Hospital, Lunenfeld-Tanenbaum and Toronto General Hospital Research Institutes, Toronto, Ontario, Canada
| | - Katherine A Siminovitch
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Mount Sinai Hospital, Lunenfeld-Tanenbaum and Toronto General Hospital Research Institutes, Toronto, Ontario, Canada
| | - Alan C Peterson
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada
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2
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Asadollahi E, Trevisiol A, Saab AS, Looser ZJ, Dibaj P, Ebrahimi R, Kusch K, Ruhwedel T, Möbius W, Jahn O, Lee JY, Don AS, Khalil MA, Hiller K, Baes M, Weber B, Abel ED, Balabio A, Popko B, Kassmann CM, Ehrenreich H, Hirrlinger J, Nave KA. Oligodendroglial fatty acid metabolism as a central nervous system energy reserve. Nat Neurosci 2024:10.1038/s41593-024-01749-6. [PMID: 39251890 DOI: 10.1038/s41593-024-01749-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 08/05/2024] [Indexed: 09/11/2024]
Abstract
Brain function requires a constant supply of glucose. However, the brain has no known energy stores, except for glycogen granules in astrocytes. In the present study, we report that continuous oligodendroglial lipid metabolism provides an energy reserve in white matter tracts. In the isolated optic nerve from young adult mice of both sexes, oligodendrocytes survive glucose deprivation better than astrocytes. Under low glucose, both axonal ATP levels and action potentials become dependent on fatty acid β-oxidation. Importantly, ongoing oligodendroglial lipid degradation feeds rapidly into white matter energy metabolism. Although not supporting high-frequency spiking, fatty acid β-oxidation in mitochondria and oligodendroglial peroxisomes protects axons from conduction blocks when glucose is limiting. Disruption of the glucose transporter GLUT1 expression in oligodendrocytes of adult mice perturbs myelin homeostasis in vivo and causes gradual demyelination without behavioral signs. This further suggests that the imbalance of myelin synthesis and degradation can underlie myelin thinning in aging and disease.
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Affiliation(s)
- Ebrahim Asadollahi
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany.
| | - Andrea Trevisiol
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
- University of Toronto, Sunnybrook Health Sciences Centre, Department of Physical Sciences, North York, Ontario, Canada
| | - Aiman S Saab
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Zoe J Looser
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Payam Dibaj
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
- Center for Rare Diseases Göttingen, Department of Pediatrics and Pediatric Neurology, Georg August University Göttingen, Göttingen, Germany
| | - Reyhane Ebrahimi
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
| | - Kathrin Kusch
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
- University of Göttingen Medical School, Institute for Auditory Neuroscience and Inner Ear Lab, Göttingen, Germany
| | - Torben Ruhwedel
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
| | - Wiebke Möbius
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
| | - Olaf Jahn
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Neurobiology, Neuroproteomics Group, Göttingen, Germany
- University Medical Center Göttingen, Department of Psychiatry and Psychotherapy, Translational Neuroproteomics Group, Göttingen, Germany
| | - Jun Yup Lee
- School of Medical Sciences and Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Anthony S Don
- School of Medical Sciences and Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Michelle-Amirah Khalil
- Department for Bioinformatics and Biochemistry, Braunschweig Integrated Center of System Biology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Karsten Hiller
- Department for Bioinformatics and Biochemistry, Braunschweig Integrated Center of System Biology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Myriam Baes
- Lab of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Bruno Weber
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - E Dale Abel
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Andrea Balabio
- Telethon Institute of Genetics and Medicine, Naples, Italy
- Department of Translational Medical Sciences, Federico II University, Naples, Italy
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Brian Popko
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Celia M Kassmann
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
| | - Hannelore Ehrenreich
- Max Planck Institute for Multidisciplinary Sciences, Clinical Neuroscience, Göttingen, Germany
- Central Institute of Mental Health, Mannheim, Germany
| | - Johannes Hirrlinger
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Klaus-Armin Nave
- Max Planck Institute for Multidisciplinary Sciences, Department of Neurogenetics, Göttingen, Germany.
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3
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Adonias GL, Siljak H, Balasubramaniam S, Barros MT. In silico modelling of neuron signal impact of cytokine storm-induced demyelination. Open Biol 2024; 14:240138. [PMID: 39226928 PMCID: PMC11371429 DOI: 10.1098/rsob.240138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 09/05/2024] Open
Abstract
In this study, we develop an in silico model of a neuron's behaviour under demyelination caused by a cytokine storm to investigate the effects of viral infections in the brain. We use a comprehensive model to measure how cytokine-induced demyelination affects the propagation of action potential (AP) signals within a neuron. We analysed the effects of neuron-neuron communications by applying information and communication theory at different levels of demyelination. Our simulations demonstrate that virus-induced degeneration can play a role in the signal power and spiking rate, which compromise the propagation and processing of information between neurons. We propose a transfer function to model the weakening effects on the AP. Our results show that demyelination induced by a cytokine storm not only degrades the signal but also impairs its propagation within the axon. Our proposed in silico model can analyse virus-induced neurodegeneration and enhance our understanding of virus-induced demyelination.
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Affiliation(s)
- Geoflly L. Adonias
- Walton Institute for Information and Communication Systems Science, South East Technology University, Waterford, Ireland
| | - Harun Siljak
- Department of Electronic and Electrical Engineering, Trinity College Dublin, Dublin, Ireland
| | | | - Michael Taynnan Barros
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK
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4
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Osso LA, Hughes EG. Dynamics of mature myelin. Nat Neurosci 2024; 27:1449-1461. [PMID: 38773349 DOI: 10.1038/s41593-024-01642-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 04/05/2024] [Indexed: 05/23/2024]
Abstract
Myelin, which is produced by oligodendrocytes, insulates axons to facilitate rapid and efficient action potential propagation in the central nervous system. Traditionally viewed as a stable structure, myelin is now known to undergo dynamic modulation throughout life. This Review examines these dynamics, focusing on two key aspects: (1) the turnover of myelin, involving not only the renewal of constituents but the continuous wholesale replacement of myelin membranes; and (2) the structural remodeling of pre-existing, mature myelin, a newly discovered form of neural plasticity that can be stimulated by external factors, including neuronal activity, behavioral experience and injury. We explore the mechanisms regulating these dynamics and speculate that myelin remodeling could be driven by an asymmetry in myelin turnover or reactivation of pathways involved in myelin formation. Finally, we outline how myelin remodeling could have profound impacts on neural function, serving as an integral component of behavioral adaptation.
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Affiliation(s)
- Lindsay A Osso
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ethan G Hughes
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA.
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5
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Wang X, Yi R, Liang X, Zhang N, Zhong F, Lu Y, Chen W, Yu T, Zhang L, Wang H, Zhou L. Myelin modulates the process of isoflurane anesthesia through the regulation of neural activity. CNS Neurosci Ther 2024; 30:e14922. [PMID: 39138640 PMCID: PMC11322027 DOI: 10.1111/cns.14922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 07/01/2024] [Accepted: 08/04/2024] [Indexed: 08/15/2024] Open
Abstract
AIMS The mechanism underlying the reversible unconsciousness induced by general anesthetics (GA) remains unclear. Recent studies revealed the critical roles of myelin and oligodendrocytes (OLs) in higher functions of the brain. However, it is unknown whether myelin actively participates in the regulation of GA. The aim of this study is to investigate the roles and possible mechanisms of myelin in the regulation of consciousness alterations induced by isoflurane anesthesia. METHODS First, demyelination models for the entire brain and specific neural nuclei were established to investigate the potential role of myelination in the regulation of GA, as well as its possible regional specificity. c-Fos staining was then performed on the demyelinated nuclei to verify the impact of myelin loss on neuronal activity. Finally, the activity of neurons during isoflurane anesthesia in demyelinated mice was recorded by optical fiber photometric calcium signal. The related behavioral indicators and EEG were recorded and analyzed. RESULTS A prolonged emergence time was observed from isoflurane anesthesia in demyelinated mice, which suggested the involvement of myelin in regulating GA. The demyelination in distinct nuclei by LPC further clarified the region-specific roles of isoflurane anesthesia regulation by myelin. The effect of demyelination on isoflurane anesthesia in the certain nucleus was consistent with that in neurons towards isoflurane anesthesia. Finally, we found that the mechanism of myelin in the modulation of isoflurane anesthesia is possibly through the regulation of neuronal activity. CONCLUSIONS In brief, myelin in the distinct neural nucleus plays an essential role in regulating the process of isoflurane anesthesia. The possible mechanism of myelin in the regulation of isoflurane anesthesia is neuronal activity modification by myelin integrity during GA. Our findings enhanced the comprehension of myelin function, and offered a fresh perspective for investigating the neural mechanisms of GA.
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Affiliation(s)
- Xu Wang
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
| | - Rulan Yi
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
| | - Xiaoling Liang
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
| | - Ning Zhang
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
| | - Fuwang Zhong
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
| | - Yali Lu
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
| | - Wenjia Chen
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
| | - Tian Yu
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
| | - Linyong Zhang
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
| | - Haiying Wang
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
| | - Liang Zhou
- Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of EducationZunyi Medical UniversityZunyiChina
- Key Laboratory of Brain ScienceZunyi Medical UniversityZunyiChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityZunyiChina
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
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6
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Cherchi F, Venturini M, Magni G, Frulloni L, Chieca M, Buonvicino D, Santalmasi C, Rossi F, De Logu F, Coppi E, Pugliese AM. Adenosine A 2B receptors differently modulate oligodendrogliogenesis and myelination depending on their cellular localization. Glia 2024. [PMID: 39077799 DOI: 10.1002/glia.24593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 07/02/2024] [Accepted: 07/03/2024] [Indexed: 07/31/2024]
Abstract
Differentiation of oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes (OLs) is a key event for axonal myelination in the brain; this process fails during demyelinating pathologies. Adenosine is emerging as an important player in oligodendrogliogenesis, by activating its metabotropic receptors (A1R, A2AR, A2BR, and A3R). We previously demonstrated that the Gs-coupled A2BR reduced differentiation of primary OPC cultures by inhibiting delayed rectifier (IK) as well as transient (IA) outward K+ currents. To deepen the unclear role of this receptor subtype in neuron-OL interplay and in myelination process, we tested the effects of different A2BR ligands in a dorsal root ganglion neuron (DRGN)/OPC cocultures, a corroborated in vitro myelination assay. The A2BR agonist, BAY60-6583, significantly reduced myelin basic protein levels but simultaneously increased myelination index in DRGN/OPC cocultures analyzed by confocal microscopy. The last effect was prevented by the selective A2BR antagonists, PSB-603 and MRS1706. To clarify this unexpected data, we wondered whether A2BRs could play a functional role on DRGNs. We first demonstrated, by immunocytochemistry, that primary DRGN monoculture expressed A2BRs. Their selective activation by BAY60-6583 enhanced DRGN excitability, as demonstrated by increased action potential firing, decreased rheobase and depolarized resting membrane potential and were prevented by PSB-603. Throughout this A2BR-dependent enhancement of neuronal activity, DRGNs could release factors to facilitate myelination processes. Finally, silencing A2BR in DRGNs alone prevents the increased myelination induced by BAY60-6583 in cocultures. In conclusion, our data suggest a different role of A2BR during oligodendrogliogenesis and myelination, depending on their activation on neurons or oligodendroglial cells.
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Affiliation(s)
- Federica Cherchi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Martina Venturini
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Giada Magni
- Cnr-Istituto di Fisica Applicata "Nello Carrara", Florence, Italy
| | - Lucia Frulloni
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Martina Chieca
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Daniela Buonvicino
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Clara Santalmasi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Francesca Rossi
- Cnr-Istituto di Fisica Applicata "Nello Carrara", Florence, Italy
| | - Francesco De Logu
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Elisabetta Coppi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Anna Maria Pugliese
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
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7
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Abdollahi N, Prescott SA. Impact of Extracellular Current Flow on Action Potential Propagation in Myelinated Axons. J Neurosci 2024; 44:e0569242024. [PMID: 38688722 PMCID: PMC11211723 DOI: 10.1523/jneurosci.0569-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024] Open
Abstract
Myelinated axons conduct action potentials, or spikes, in a saltatory manner. Inward current caused by a spike occurring at one node of Ranvier spreads axially to the next node, which regenerates the spike when depolarized enough for voltage-gated sodium channels to activate, and so on. The rate at which this process progresses dictates the velocity at which the spike is conducted and depends on several factors including axial resistivity and axon diameter that directly affect axial current. Here we show through computational simulations in modified double-cable axon models that conduction velocity also depends on extracellular factors whose effects can be explained by their indirect influence on axial current. Specifically, we show that a conventional double-cable model, with its outside layer connected to ground, transmits less axial current than a model whose outside layer is less absorptive. A more resistive barrier exists when an axon is packed tightly between other myelinated fibers, for example. We show that realistically resistive boundary conditions can significantly increase the velocity and energy efficiency of spike propagation, while also protecting against propagation failure. Certain factors like myelin thickness may be less important than typically thought if extracellular conditions are more resistive than normally considered. We also show how realistically resistive boundary conditions affect ephaptic interactions. Overall, these results highlight the unappreciated importance of extracellular conditions for axon function.
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Affiliation(s)
- Nooshin Abdollahi
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Steven A Prescott
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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8
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Xu Q, Xi Y, Wang L, Xu M, Ruan T, Du Z, Jiang C, Cao J, Zhu X, Wang X, Yang B, Liu J. In situ self-referenced intracellular two-electrode system for enhanced accuracy in single-cell analysis. Biosens Bioelectron 2024; 253:116173. [PMID: 38432075 DOI: 10.1016/j.bios.2024.116173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/19/2024] [Accepted: 02/26/2024] [Indexed: 03/05/2024]
Abstract
Since the emergence of single-cell electroanalysis, the two-electrode system has become the predominant electrochemical system for real-time behavioral analysis of single-cell and multicellular populations. However, due to the transmembrane placement of the two electrodes, cellular activities can be interrupted by the transmembrane potentials, and the test results are susceptible to influences from factors such as intracellular solution, membrane, and bulk solution. These limitations impede the advancement of single-cell analysis. Here, we propose a highly miniaturized and integrated in situ self-referenced intracellular two-electrode system (IS-SRITES), wherein both the working and reference electrodes are positioned inside the cell. Additionally, we demonstrated the stability (0.28 mV/h) of the solid-contact in situ Ag/AgCl reference electrode and the ability of the system to conduct standard electrochemical testing in a wide pH range (pH 6.0-8.0). Cell experiments confirmed the non-destructive performance of the electrode system towards cells and its capacity for real-time monitoring of intra- and extracellular pH values. Moreover, through equivalent circuits, finite element simulations, and drug delivery experiments, we illustrated that the IS-SRITES can yield more accurate test results and exhibit enhanced resistance to interference from the extracellular environment. Our proposed system holds the potential to enable the precise detection of intracellular substances and optimize the existing model of the electrode system for intracellular signal detection, thereby spearheading advancements in single-cell analysis.
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Affiliation(s)
- Qingda Xu
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ye Xi
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Longchun Wang
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Mengfei Xu
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tao Ruan
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhiyuan Du
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chunpeng Jiang
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiawei Cao
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiantao Zhu
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China; Department of Micro/Nano Electronics, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaolin Wang
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bin Yang
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jingquan Liu
- National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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9
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Khelfaoui H, Ibaceta-Gonzalez C, Angulo MC. Functional myelin in cognition and neurodevelopmental disorders. Cell Mol Life Sci 2024; 81:181. [PMID: 38615095 PMCID: PMC11016012 DOI: 10.1007/s00018-024-05222-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/18/2024] [Accepted: 03/30/2024] [Indexed: 04/15/2024]
Abstract
In vertebrates, oligodendrocytes (OLs) are glial cells of the central nervous system (CNS) responsible for the formation of the myelin sheath that surrounds the axons of neurons. The myelin sheath plays a crucial role in the transmission of neuronal information by promoting the rapid saltatory conduction of action potentials and providing neurons with structural and metabolic support. Saltatory conduction, first described in the peripheral nervous system (PNS), is now generally recognized as a universal evolutionary innovation to respond quickly to the environment: myelin helps us think and act fast. Nevertheless, the role of myelin in the central nervous system, especially in the brain, may not be primarily focused on accelerating conduction speed but rather on ensuring precision. Its principal function could be to coordinate various neuronal networks, promoting their synchronization through oscillations (or rhythms) relevant for specific information processing tasks. Interestingly, myelin has been directly involved in different types of cognitive processes relying on brain oscillations, and myelin plasticity is currently considered to be part of the fundamental mechanisms for memory formation and maintenance. However, despite ample evidence showing the involvement of myelin in cognition and neurodevelopmental disorders characterized by cognitive impairments, the link between myelin, brain oscillations, cognition and disease is not yet fully understood. In this review, we aim to highlight what is known and what remains to be explored to understand the role of myelin in high order brain processes.
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Affiliation(s)
- Hasni Khelfaoui
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France
| | - Cristobal Ibaceta-Gonzalez
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France
| | - Maria Cecilia Angulo
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France.
- GHU-PARIS Psychiatrie Et Neurosciences, Hôpital Sainte Anne, 75014, Paris, France.
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10
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Mateus JC, Sousa MM, Burrone J, Aguiar P. Beyond a Transmission Cable-New Technologies to Reveal the Richness in Axonal Electrophysiology. J Neurosci 2024; 44:e1446232023. [PMID: 38479812 PMCID: PMC10941245 DOI: 10.1523/jneurosci.1446-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 03/17/2024] Open
Abstract
The axon is a neuronal structure capable of processing, encoding, and transmitting information. This assessment contrasts with a limiting, but deeply rooted, perspective where the axon functions solely as a transmission cable of somatodendritic activity, sending signals in the form of stereotypical action potentials. This perspective arose, at least partially, because of the technical difficulties in probing axons: their extreme length-to-diameter ratio and intricate growth paths preclude the study of their dynamics through traditional techniques. Recent findings are challenging this view and revealing a much larger repertoire of axonal computations. Axons display complex signaling processes and structure-function relationships, which can be modulated via diverse activity-dependent mechanisms. Additionally, axons can exhibit patterns of activity that are dramatically different from those of their corresponding soma. Not surprisingly, many of these recent discoveries have been driven by novel technology developments, which allow for in vitro axon electrophysiology with unprecedented spatiotemporal resolution and signal-to-noise ratio. In this review, we outline the state-of-the-art in vitro toolset for axonal electrophysiology and summarize the recent discoveries in axon function it has enabled. We also review the increasing repertoire of microtechnologies for controlling axon guidance which, in combination with the available cutting-edge electrophysiology and imaging approaches, have the potential for more controlled and high-throughput in vitro studies. We anticipate that a larger adoption of these new technologies by the neuroscience community will drive a new era of experimental opportunities in the study of axon physiology and consequently, neuronal function.
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Affiliation(s)
- J C Mateus
- i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - M M Sousa
- i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - J Burrone
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, United Kingdom
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, United Kingdom
| | - P Aguiar
- i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
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11
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Looser ZJ, Faik Z, Ravotto L, Zanker HS, Jung RB, Werner HB, Ruhwedel T, Möbius W, Bergles DE, Barros LF, Nave KA, Weber B, Saab AS. Oligodendrocyte-axon metabolic coupling is mediated by extracellular K + and maintains axonal health. Nat Neurosci 2024; 27:433-448. [PMID: 38267524 PMCID: PMC10917689 DOI: 10.1038/s41593-023-01558-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/13/2023] [Indexed: 01/26/2024]
Abstract
The integrity of myelinated axons relies on homeostatic support from oligodendrocytes (OLs). To determine how OLs detect axonal spiking and how rapid axon-OL metabolic coupling is regulated in the white matter, we studied activity-dependent calcium (Ca2+) and metabolite fluxes in the mouse optic nerve. We show that fast axonal spiking triggers Ca2+ signaling and glycolysis in OLs. OLs detect axonal activity through increases in extracellular potassium (K+) concentrations and activation of Kir4.1 channels, thereby regulating metabolite supply to axons. Both pharmacological inhibition and OL-specific inactivation of Kir4.1 reduce the activity-induced axonal lactate surge. Mice lacking oligodendroglial Kir4.1 exhibit lower resting lactate levels and altered glucose metabolism in axons. These early deficits in axonal energy metabolism are associated with late-onset axonopathy. Our findings reveal that OLs detect fast axonal spiking through K+ signaling, making acute metabolic coupling possible and adjusting the axon-OL metabolic unit to promote axonal health.
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Affiliation(s)
- Zoe J Looser
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Zainab Faik
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Luca Ravotto
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Henri S Zanker
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dwight E Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - L Felipe Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.
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12
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Furusho M, Terasaki M. Evidence for glia-mediated, age-dependent remodeling of myelin at the axon initial segment. J Comp Neurol 2024; 532:e25574. [PMID: 38411251 DOI: 10.1002/cne.25574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 11/02/2023] [Accepted: 12/07/2023] [Indexed: 02/28/2024]
Abstract
Due to its proximity to the axon initial segment (AIS), the paranode of the first myelin segment can influence the threshold for action potentials and how a neuron participates in a neuronal circuit. Using serial section electron microscopy, we examined its three-dimensional (3D) organization in the ventral horn of the mouse spinal cord. The myelin loops of postnatal day 18 mice resemble those at the node of Ranvier. However, in 3-month-old mice, 13 of 22 para-AIS showed 4 types of alteration: (A) A cytoplasmic foot process, with ultrastructural characteristics of an astrocyte, was interposed between the axolemma and the myelin loops. (B) A thin extension of the inner tongue was present between the foot process and axolemma. (C) The foot process was absent. The inner tongue extension was a broad lamella from which a thin extension reached beyond the loops and spiraled around axon. (D) One set of loops was adjacent to the axon, and another was further back and underlain by compact myelin. We suggest that (A)-(C) are steps in a progression toward (D). In this progression, a glial process displaces the original loops, the inner tongue reactivates and extends beneath the foot process, then wraps around the axon to form a new set of loops. This is the first study of the 3D organization of myelin at the AIS and provides evidence for glia-mediated age-dependent remodeling at this critical region.
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Affiliation(s)
- Miki Furusho
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Mark Terasaki
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut, USA
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13
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Lohse A, Deininger MM, Loeser J, Roehren F, Ziles D, Breuer T, Leonhardt S, Walter M. A physiological model of phrenic nerve excitation by electrical stimulation. Biomed Phys Eng Express 2024; 10:025017. [PMID: 38232399 DOI: 10.1088/2057-1976/ad1fa3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 01/17/2024] [Indexed: 01/19/2024]
Abstract
Mechanical ventilation is essential in intensive care treatment but leads to diaphragmatic atrophy, which in turn contributes to prolonged weaning and increased mortality. One approach to prevent diaphragmatic atrophy while achieving pulmonary ventilation is electrical stimulation of the phrenic nerve. To automize phrenic nerve stimulation resulting in lung protective tidal volumes with lowest possible currents, mathematical models are required. Nerve stimulation models are often complex, so many parameters have to be identified prior to implementation. This paper presents a novel, simplified approach to model phrenic nerve excitation to obtain an individualized patient model using a few data points. The latter is based on the idea that nerve fibers are excited when the electric field exceeds a threshold. The effect of the geometry parameter on the model output was analyzed, and the model was validated with measurement data from a pig trial (RMSE in between 0.44 × 10-2and 1.64 × 10-2for parameterized models). The modeled phrenic nerve excitation behaved similarly to the measured tidal volumes, and thus could be used to develop automated phrenic nerve stimulation systems for lung protective ventilation.
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Affiliation(s)
- Arnhold Lohse
- Chair for Medical Information Technology, Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Aachen, 52074, Germany
| | - Matthias Manfred Deininger
- Department of Intensive and Intermediate Care, Medical Faculty, RWTH Aachen University, Aachen, 52074, Germany
| | - Johannes Loeser
- Institute of Automatic Control, Faculty of Mechanical Engineering, RWTH Aachen University, Aachen, 52074, Germany
| | - Felix Roehren
- Chair for Medical Information Technology, Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Aachen, 52074, Germany
| | - Dmitrij Ziles
- Department of Intensive and Intermediate Care, Medical Faculty, RWTH Aachen University, Aachen, 52074, Germany
| | - Thomas Breuer
- Department of Intensive and Intermediate Care, Medical Faculty, RWTH Aachen University, Aachen, 52074, Germany
| | - Steffen Leonhardt
- Chair for Medical Information Technology, Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Aachen, 52074, Germany
| | - Marian Walter
- Chair for Medical Information Technology, Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Aachen, 52074, Germany
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14
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Kim YW, Park JM, Park CS, Na H, Kang YW, Lee W, Sun JY. Anisotropically Conductive Hydrogels with Directionally Aligned PEDOT:PSS in a PVA Matrix. ACS APPLIED MATERIALS & INTERFACES 2024; 16:4013-4023. [PMID: 38189267 DOI: 10.1021/acsami.3c16094] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Electrical anisotropy, which is characterized by the efficient transmission of electrical signals in specific directions, is prevalent in both natural and engineered systems. However, traditional anisotropically conductive materials are often rigid and dry, thus limiting their utility in applications aiming for the seamless integration of various technologies with biological tissues. In the present study, we introduce a method for precisely controlling the microstructures of conductive and insulating polymers to create highly anisotropically conductive composite hydrogels. Our methodology involves combining aligned poly(vinyl alcohol) microfibrils, infused poly(3,4-ethylenedioxythiophene) polystyrenesulfonate, and sodium citrate precipitation to form dense, aligned conductive paths. This significantly enhances the electrical conductivity anisotropy (σ∥/σ⊥ ≈ 60.8) within these composite hydrogels.
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Affiliation(s)
- Yong-Woo Kim
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae-Man Park
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Chang Seo Park
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyeonuk Na
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Yong-Woo Kang
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Wooseop Lee
- Pohang Accelerator Laboratory, POSTECH, Pohang 37673, Republic of Korea
| | - Jeong-Yun Sun
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
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15
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Das S, Maharatna K. Filtering property of myelinated internode can change neural information representability and might trigger a compensatory action during demyelination. Sci Rep 2023; 13:22227. [PMID: 38097640 PMCID: PMC10721845 DOI: 10.1038/s41598-023-49208-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 12/05/2023] [Indexed: 12/17/2023] Open
Abstract
In this paper, for the first time, we showed that an Internode Segment (INS) of a myelinated axon acts as a lowpass filter, and its filter characteristics depend on the number of myelin turns. Consequently, we showed how the representability of a neural signal could be altered with myelin loss in pathological conditions involving demyelinating diseases. Contrary to the traditionally held viewpoint that myelin geometry of an INS is optimised for maximising Conduction Velocity (CV) of Action Potential (AP), our theory provides an alternative viewpoint that myelin geometry of an INS is optimised for maximizing representability of the stimuli a fibre is meant to carry. Subsequently, we show that this new viewpoint could explain hitherto unexplained experimentally observed phenomena such as, shortening of INS length during demyelination and remyelination, and non-uniform distribution of INS in the central nervous system fibres and associated changes in diameter of nodes of ranvier along an axon. Finally, our theory indicates that a compensatory action could take place during demyelination up to a certain number of loss of myelin turns to preserve the neural signal representability by simultaneous linear scaling of the length of an INS and the inner radius of the fibre.
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Affiliation(s)
- Sarbani Das
- School of Electronics and Computer Science, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Koushik Maharatna
- School of Electronics and Computer Science, University of Southampton, University Road, Southampton, SO17 1BJ, UK.
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16
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Nave KA, Asadollahi E, Sasmita A. Expanding the function of oligodendrocytes to brain energy metabolism. Curr Opin Neurobiol 2023; 83:102782. [PMID: 37703600 DOI: 10.1016/j.conb.2023.102782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 09/15/2023]
Abstract
Oligodendrocytes are best known for wrapping myelin, a unique specialization that enables energy-efficient and fast axonal impulse propagation in white matter tracts and fibers of the cortical circuitry. However, myelinating oligodendrocytes have additional metabolic functions that are only gradually understood, including the regulated release of pyruvate/lactate and extracellular vesicles, both of which are in support of the axonal energy balance. The axon-supportive functions of glial cells are older than myelin in nervous system evolution and implicate oligodendrocyte dysfunction and loss of myelin integrity as a risk factor for progressive neurodegeneration in brain diseases.
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Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen.
| | - Ebrahim Asadollahi
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen. https://twitter.com/EbrahimAsadoll3
| | - Andrew Sasmita
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen. https://twitter.com/AOSasmita
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17
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Ames S, Adams K, Geisen ME, Stirling DP. Ca 2+-induced myelin pathology precedes axonal spheroid formation and is mediated in part by store-operated Ca 2+ entry after spinal cord injury. Neural Regen Res 2023; 18:2720-2726. [PMID: 37449636 DOI: 10.4103/1673-5374.373656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
The formation of axonal spheroid is a common feature following spinal cord injury. To further understand the source of Ca2+ that mediates axonal spheroid formation, we used our previously characterized ex vivo mouse spinal cord model that allows precise perturbation of extracellular Ca2+. We performed two-photon excitation imaging of spinal cords isolated from Thy1YFP+ transgenic mice and applied the lipophilic dye, Nile red, to record dynamic changes in dorsal column axons and their myelin sheaths respectively. We selectively released Ca2+ from internal stores using the Ca2+ ionophore ionomycin in the presence or absence of external Ca2+. We reported that ionomycin dose-dependently induces pathological changes in myelin and pronounced axonal spheroid formation in the presence of normal 2 mM Ca2+ artificial cerebrospinal fluid. In contrast, removal of external Ca2+ significantly decreased ionomycin-induced myelin and axonal spheroid formation at 2 hours but not at 1 hour after treatment. Using mice that express a neuron-specific Ca2+ indicator in spinal cord axons, we confirmed that ionomycin induced significant increases in intra-axonal Ca2+, but not in the absence of external Ca2+. Periaxonal swelling and the resultant disruption in the axo-myelinic interface often precedes and is negatively correlated with axonal spheroid formation. Pretreatment with YM58483 (500 nM), a well-established blocker of store-operated Ca2+ entry, significantly decreased myelin injury and axonal spheroid formation. Collectively, these data reveal that ionomycin-induced depletion of internal Ca2+ stores and subsequent external Ca2+ entry through store-operated Ca2+ entry contributes to pathological changes in myelin and axonal spheroid formation, providing new targets to protect central myelinated fibers.
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Affiliation(s)
- Spencer Ames
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Kia Adams
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Mariah E Geisen
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY, USA
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery; Anatomical Sciences and Neurobiology; Microbiology and Immunology, University of Louisville, School of Medicine, Louisville, KY, USA
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18
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Fan C, An H, Kim D, Park Y. Uncovering oligodendrocyte enhancers that control Cnp expression. Hum Mol Genet 2023; 32:3225-3236. [PMID: 37642363 PMCID: PMC10656706 DOI: 10.1093/hmg/ddad141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/05/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Oligodendrocytes (OLs) produce myelin sheaths around axons in the central nervous system (CNS). Myelin accelerates the propagation of action potentials along axons and supports the integrity of axons. Impaired myelination has been linked to neurological and neuropsychiatric disorders. As a major component of CNS myelin, 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) plays an indispensable role in the axon-supportive function of myelin. Notably, this function requires a high-level expression of CNP in OLs, as evidenced by downregulated expression of CNP in mental disorders and animal models. Little is known about how CNP expression is regulated in OLs. Especially, OL enhancers that govern CNP remain elusive. We have recently developed a powerful method that links OL enhancers to target genes in a principled manner. Here, we applied it to Cnp, uncovering two OL enhancers for it (termed Cnp-E1 and Cnp-E2). Epigenome editing analysis revealed that Cnp-E1 and Cnp-E2 are dedicated to Cnp. ATAC-seq and ChIP-seq data show that Cnp-E1 and Cnp-E2 are conserved OL-specific enhancers. Single cell multi-omics data that jointly profile gene expression and chromatin accessibility suggest that Cnp-E2 plays an important role in Cnp expression in the early stage of OL differentiation while Cnp-E1 sustains it in mature OLs.
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Affiliation(s)
- Chuandong Fan
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
| | - Hongjoo An
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
| | - Dongkyeong Kim
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Yungki Park
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
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19
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Liang L, Damiani A, Del Brocco M, Rogers ER, Jantz MK, Fisher LE, Gaunt RA, Capogrosso M, Lempka SF, Pirondini E. A systematic review of computational models for the design of spinal cord stimulation therapies: from neural circuits to patient-specific simulations. J Physiol 2023; 601:3103-3121. [PMID: 36409303 PMCID: PMC10259770 DOI: 10.1113/jp282884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 11/08/2022] [Indexed: 08/02/2023] Open
Abstract
Seventy years ago, Hodgkin and Huxley published the first mathematical model to describe action potential generation, laying the foundation for modern computational neuroscience. Since then, the field has evolved enormously, with studies spanning from basic neuroscience to clinical applications for neuromodulation. Computer models of neuromodulation have evolved in complexity and personalization, advancing clinical practice and novel neurostimulation therapies, such as spinal cord stimulation. Spinal cord stimulation is a therapy widely used to treat chronic pain, with rapidly expanding indications, such as restoring motor function. In general, simulations contributed dramatically to improve lead designs, stimulation configurations, waveform parameters and programming procedures and provided insight into potential mechanisms of action of electrical stimulation. Although the implementation of neural models are relentlessly increasing in number and complexity, it is reasonable to ask whether this observed increase in complexity is necessary for improved accuracy and, ultimately, for clinical efficacy. With this aim, we performed a systematic literature review and a qualitative meta-synthesis of the evolution of computational models, with a focus on complexity, personalization and the use of medical imaging to capture realistic anatomy. Our review showed that increased model complexity and personalization improved both mechanistic and translational studies. More specifically, the use of medical imaging enabled the development of patient-specific models that can help to transform clinical practice in spinal cord stimulation. Finally, we combined our results to provide clear guidelines for standardization and expansion of computational models for spinal cord stimulation.
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Affiliation(s)
- Lucy Liang
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Arianna Damiani
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Matteo Del Brocco
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Evan R Rogers
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Maria K Jantz
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Lee E Fisher
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert A Gaunt
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Marco Capogrosso
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - Elvira Pirondini
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
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20
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Sonawane K, Dixit H, Jayaraj A, Thota N, Sekar C. "Knowing It Before Blocking It," the ABCD of the Peripheral Nerves: Part A (Nerve Anatomy and Physiology). Cureus 2023; 15:e41771. [PMID: 37575775 PMCID: PMC10416754 DOI: 10.7759/cureus.41771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2023] [Indexed: 08/15/2023] Open
Abstract
Regional anesthesia (RA) is an interplay between the local anesthetic (LA) solution and the neural structures, resulting in nerve conduction blockade. For that, it is necessary to understand which hurdles the LA has to overcome and which components of the nerves are involved. Background knowledge of the neural and non-neural components of the nerve helps locate the safest area for LA deposition. In addition, knowledge of nerve physiology and the conduction process helps to understand the patterns of block onset, involved fibers, and block regression. Neural connective tissue protects the nerve on the one hand and influences the overall effect of the blockade and the occurrence of nerve injuries on the other. The arrangement of the nerve fibers explains the science behind the differential blockage after LA deposition. This article describes the important aspects of nerve anatomy (nerve formation and composition) and nerve physiology (impulse generation and propagation). It also provides insight into the physiological processes involved when a damaged neural structure leads to potential clinical symptoms. It will help readers sharpen their skills and knowledge to execute safe RA without damaging any vital structures in the nerve.
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Affiliation(s)
- Kartik Sonawane
- Anesthesiology, Ganga Medical Centre and Hospitals, Pvt. Ltd., Coimbatore, IND
| | - Hrudini Dixit
- Anesthesiology, Sir H. N. Reliance Foundation Hospital and Research Centre, Mumbai, IND
| | - Aparna Jayaraj
- Anesthesiology, Ganga Medical Centre and Hospitals, Pvt. Ltd., Coimbatore, IND
| | - Navya Thota
- Anesthesiology, Ganga Medical Centre and Hospitals, Pvt. Ltd., Coimbatore, IND
| | - Chelliah Sekar
- Anesthesiology, Ganga Medical Centre and Hospitals Pvt. Ltd., Coimbatore, IND
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21
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Jiang L, Li F, Chen Z, Zhu B, Yi C, Li Y, Zhang T, Peng Y, Si Y, Cao Z, Chen A, Yao D, Chen X, Xu P. Information transmission velocity-based dynamic hierarchical brain networks. Neuroimage 2023; 270:119997. [PMID: 36868393 DOI: 10.1016/j.neuroimage.2023.119997] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/09/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The brain functions as an accurate circuit that regulates information to be sequentially propagated and processed in a hierarchical manner. However, it is still unknown how the brain is hierarchically organized and how information is dynamically propagated during high-level cognition. In this study, we developed a new scheme for quantifying the information transmission velocity (ITV) by combining electroencephalogram (EEG) and diffusion tensor imaging (DTI), and then mapped the cortical ITV network (ITVN) to explore the information transmission mechanism of the human brain. The application in MRI-EEG data of P300 revealed bottom-up and top-down ITVN interactions subserving P300 generation, which was comprised of four hierarchical modules. Among these four modules, information exchange between visual- and attention-activated regions occurred at a high velocity, related cognitive processes could thus be efficiently accomplished due to the heavy myelination of these regions. Moreover, inter-individual variability in P300 was probed to be attributed to the difference in information transmission efficiency of the brain, which may provide new insight into the cognitive degenerations in clinical neurodegenerative disorders, such as Alzheimer's disease, from the transmission velocity perspective. Together, these findings confirm the capacity of ITV to effectively determine the efficiency of information propagation in the brain.
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Affiliation(s)
- Lin Jiang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Fali Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhaojin Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Bin Zhu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Chanlin Yi
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yuqin Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Tao Zhang
- School of science, Xihua University, Chengdu 610039, China
| | - Yueheng Peng
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yajing Si
- School of Psychology, Xinxiang Medical University, Xinxiang 453003, China
| | - Zehong Cao
- STEM, University of South Australia, Adelaide, SA 5000, Australia
| | - Antao Chen
- Faculty of Psychology, Southwest University, Chongqing 400715, China
| | - Dezhong Yao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China; School of Electrical Engineering, Zhengzhou University, Zhengzhou 450001, China; Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, Chengdu 2019RU035, China.
| | - Xun Chen
- Department of Neurosurgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China; Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei 230026, China.
| | - Peng Xu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China.
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22
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Dutta S, Hornung S, Taha HB, Bitan G. Biomarkers for parkinsonian disorders in CNS-originating EVs: promise and challenges. Acta Neuropathol 2023; 145:515-540. [PMID: 37012443 PMCID: PMC10071251 DOI: 10.1007/s00401-023-02557-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/27/2023] [Accepted: 03/07/2023] [Indexed: 04/05/2023]
Abstract
Extracellular vesicles (EVs), including exosomes, microvesicles, and oncosomes, are nano-sized particles enclosed by a lipid bilayer. EVs are released by virtually all eukaryotic cells and have been shown to contribute to intercellular communication by transporting proteins, lipids, and nucleic acids. In the context of neurodegenerative diseases, EVs may carry toxic, misfolded forms of amyloidogenic proteins and facilitate their spread to recipient cells in the central nervous system (CNS). CNS-originating EVs can cross the blood-brain barrier into the bloodstream and may be found in other body fluids, including saliva, tears, and urine. EVs originating in the CNS represent an attractive source of biomarkers for neurodegenerative diseases, because they contain cell- and cell state-specific biological materials. In recent years, multiple papers have reported the use of this strategy for identification and quantitation of biomarkers for neurodegenerative diseases, including Parkinson's disease and atypical parkinsonian disorders. However, certain technical issues have yet to be standardized, such as the best surface markers for isolation of cell type-specific EVs and validating the cellular origin of the EVs. Here, we review recent research using CNS-originating EVs for biomarker studies, primarily in parkinsonian disorders, highlight technical challenges, and propose strategies for overcoming them.
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Affiliation(s)
- Suman Dutta
- International Institute of Innovation and Technology, New Town, Kolkata, India
| | - Simon Hornung
- Division of Peptide Biochemistry, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Hash Brown Taha
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California Los Angeles, 635 Charles E. Young Drive South/Gordon 451, Los Angeles, CA, 90095, USA
| | - Gal Bitan
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California Los Angeles, 635 Charles E. Young Drive South/Gordon 451, Los Angeles, CA, 90095, USA.
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA.
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, USA.
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23
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Kozar-Gillan N, Velichkova A, Kanatouris G, Eshed-Eisenbach Y, Steel G, Jaegle M, Aunin E, Peles E, Torsney C, Meijer DN. LGI3/2-ADAM23 interactions cluster Kv1 channels in myelinated axons to regulate refractory period. J Cell Biol 2023; 222:e202211031. [PMID: 36828548 PMCID: PMC9997507 DOI: 10.1083/jcb.202211031] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/18/2022] [Accepted: 01/17/2023] [Indexed: 02/26/2023] Open
Abstract
Along myelinated axons, Shaker-type potassium channels (Kv1) accumulate at high density in the juxtaparanodal region, directly adjacent to the paranodal axon-glia junctions that flank the nodes of Ranvier. However, the mechanisms that control the clustering of Kv1 channels, as well as their function at this site, are still poorly understood. Here we demonstrate that axonal ADAM23 is essential for both the accumulation and stability of juxtaparanodal Kv1 complexes. The function of ADAM23 is critically dependent on its interaction with its extracellular ligands LGI2 and LGI3. Furthermore, we demonstrate that juxtaparanodal Kv1 complexes affect the refractory period, thus enabling high-frequency burst firing of action potentials. Our findings not only reveal a previously unknown molecular pathway that regulates Kv1 channel clustering, but they also demonstrate that the juxtaparanodal Kv1 channels that are concealed below the myelin sheath, play a significant role in modifying axonal physiology.
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Affiliation(s)
- Nina Kozar-Gillan
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
| | | | - George Kanatouris
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology and Molecular Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Gavin Steel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
| | | | - Eerik Aunin
- Biomedical Sciences, ErasmusMC, Rotterdam, Netherlands
| | - Elior Peles
- Department of Molecular Cell Biology and Molecular Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Carole Torsney
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh. UK
| | - Dies N. Meijer
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
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24
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Stirling DP. Potential physiological and pathological roles for axonal ryanodine receptors. Neural Regen Res 2023; 18:756-759. [PMID: 36204832 PMCID: PMC9700104 DOI: 10.4103/1673-5374.354512] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/02/2022] [Accepted: 06/23/2022] [Indexed: 11/04/2022] Open
Abstract
Clinical disability following trauma or disease to the spinal cord often involves the loss of vital white matter elements including axons and glia. Although excessive Ca2+ is an established driver of axonal degeneration, therapeutically targeting externally sourced Ca2+ to date has had limited success in both basic and clinical studies. Contributing factors that may underlie this limited success include the complexity of the many potential sources of Ca2+ entry and the discovery that axons also contain substantial amounts of stored Ca2+ that if inappropriately released could contribute to axonal demise. Axonal Ca2+ storage is largely accomplished by the axoplasmic reticulum that is part of a continuous network of the endoplasmic reticulum that provides a major sink and source of intracellular Ca2+ from the tips of dendrites to axonal terminals. This "neuron-within-a-neuron" is positioned to rapidly respond to diverse external and internal stimuli by amplifying cytosolic Ca2+ levels and generating short and long distance regenerative Ca2+ waves through Ca2+ induced Ca2+ release. This review provides a glimpse into the molecular machinery that has been implicated in regulating ryanodine receptor mediated Ca2+ release in axons and how dysregulation and/or overstimulation of these internodal axonal signaling nanocomplexes may directly contribute to Ca2+-dependent axonal demise. Neuronal ryanodine receptors expressed in dendrites, soma, and axonal terminals have been implicated in synaptic transmission and synaptic plasticity, but a physiological role for internodal localized ryanodine receptors remains largely obscure. Plausible physiological roles for internodal ryanodine receptors and such an elaborate internodal binary membrane signaling network in axons will also be discussed.
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Affiliation(s)
- David P. Stirling
- Kentucky Spinal Cord Injury Research Center and Departments of Neurological Surgery, Anatomical Sciences and Neurobiology, Microbiology and Immunology, University of Louisville, School of Medicine, Louisville, KY, USA
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25
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Myelinated axon as a plastic cable regulating brain functions. Neurosci Res 2023; 187:45-51. [PMID: 36347403 DOI: 10.1016/j.neures.2022.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022]
Abstract
Each oligodendrocyte (OC) forms myelin approximately in around 10 different axons to coordinate information transfer by regulating conduction velocity in the central nervous system (CNS). In the classical view, myelin has been considered a static structure that rarely turns over under healthy conditions because myelin tightly holds axons by their laminar complex structure. However, in recent decades, the classical views of static myelin have been renewed with pioneering studies that showed plastic changes in myelin throughout life with new experiences, such as the acquisition of new motor skills and the formation of memory. These changes in myelin regulate conduction velocity to optimize the temporal pattern of neuronal circuit activity among distinct brain regions associated with skill learning and memory. Here, we introduce pioneering studies and discuss the implications of plastic myelin on neural circuits and brain function.
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26
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Djannatian M, Radha S, Weikert U, Safaiyan S, Wrede C, Deichsel C, Kislinger G, Rhomberg A, Ruhwedel T, Campbell DS, van Ham T, Schmid B, Hegermann J, Möbius W, Schifferer M, Simons M. Myelination generates aberrant ultrastructure that is resolved by microglia. J Biophys Biochem Cytol 2023; 222:213804. [PMID: 36637807 PMCID: PMC9856851 DOI: 10.1083/jcb.202204010] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 10/18/2022] [Accepted: 12/21/2022] [Indexed: 01/14/2023] Open
Abstract
To enable rapid propagation of action potentials, axons are ensheathed by myelin, a multilayered insulating membrane formed by oligodendrocytes. Most of the myelin is generated early in development, resulting in the generation of long-lasting stable membrane structures. Here, we explored structural and dynamic changes in central nervous system myelin during development. To achieve this, we performed an ultrastructural analysis of mouse optic nerves by serial block face scanning electron microscopy (SBF-SEM) and confocal time-lapse imaging in the zebrafish spinal cord. We found that myelin undergoes extensive ultrastructural changes during early postnatal development. Myelin degeneration profiles were engulfed and phagocytosed by microglia using exposed phosphatidylserine as one "eat me" signal. In contrast, retractions of entire myelin sheaths occurred independently of microglia and involved uptake of myelin by the oligodendrocyte itself. Our findings show that the generation of myelin early in development is an inaccurate process associated with aberrant ultrastructural features that require substantial refinement.
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Affiliation(s)
- Minou Djannatian
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany,Department of Neurology, Klinikum rechts der Isar, TUM School of Medicine, Technical University of Munich, Munich, Germany,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany,Minou Djannatian:
| | - Swathi Radha
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Ulrich Weikert
- Max-Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Shima Safaiyan
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Christoph Wrede
- https://ror.org/00f2yqf98Institute of Functional and Applied Anatomy, Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Cassandra Deichsel
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Georg Kislinger
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Agata Rhomberg
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Torben Ruhwedel
- Max-Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Douglas S. Campbell
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Tjakko van Ham
- https://ror.org/018906e22Department of Clinical Genetics, Erasmus University Medical Center, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Bettina Schmid
- https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany
| | - Jan Hegermann
- https://ror.org/00f2yqf98Institute of Functional and Applied Anatomy, Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Wiebke Möbius
- Max-Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Martina Schifferer
- https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,https://ror.org/043j0f473German Center for Neurodegenerative Diseases, Munich, Germany,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany,Institute for Stroke and Dementia Research, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany,Correspondence to Mikael Simons:
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27
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Bigbee JW. Cells of the Central Nervous System: An Overview of Their Structure and Function. ADVANCES IN NEUROBIOLOGY 2023; 29:41-64. [PMID: 36255671 DOI: 10.1007/978-3-031-12390-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The central nervous system is the last major organ system in the vertebrate body to yield its cellular structure, due to the complexity of its cells and their interactions. The fundamental unit of the nervous system is the neuron, which forms complex circuits that receive and integrate information and generate adaptive responses. Each neuron is composed of an input domain consisting of multiple dendrites along with the cell body, which is also responsible for the majority of macromolecule synthesis for the cell. The output domain is the axon which is a singular extension from the cell body that propagates the action potential to the synapse, where signals pass from one neuron to another. Facilitating these functions are cohorts of supporting cells consisting of astrocytes, oligodendrocytes and microglia along with NG2 cells and ependymal cells. Astrocytes have a dazzling array of functions including physical support, maintenance of homeostasis, development and integration of synaptic activity. Oligodendrocytes form the myelin sheath which surrounds axons and enables rapid conduction of the nerve impulse. Microglia are the resident immune cells, providing immune surveillance and remodeling of neuronal circuits during development and trauma. All these cells function in concert with each other, producing the remarkably diverse functions of the nervous system.
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Affiliation(s)
- John W Bigbee
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA.
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28
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Kwon J, Lee S, Jo Y, Choi M. All-optical observation on activity-dependent nanoscale dynamics of myelinated axons. NEUROPHOTONICS 2023; 10:015003. [PMID: 36699624 PMCID: PMC9868287 DOI: 10.1117/1.nph.10.1.015003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
SIGNIFICANCE In the mammalian brain, rapid conduction of neural information is supported by the myelin, the functional efficacy of which shows steep dependence on its nanoscale cytoarchitecture. Although previous in vitro studies have suggested that neural activity accompanies nanometer-scale cellular deformations, whether neural activity can dynamically remodel the myelinated axon has remained unexplored due to the technical challenge in observing its nanostructural dynamics in living tissues. AIM We aim to observe activity-dependent nanostructural dynamics of myelinated axons in a living brain tissue. APPROACH We introduced a novel all-optical approach combining a nanoscale dynamic readout based on spectral interferometry and optogenetic control of neural excitation in an acute brain slice preparation. RESULTS In response to optogenetically evoked neuronal burst firing, the myelinated axons exhibited progressive and reversible spectral redshifts, corresponding to the transient swelling at a subnanometer scale. We further revealed that the activity-dependent nanostructural dynamics was localized to the paranode. CONCLUSIONS Our all-optical studies substantiate that myelinated axon exhibits activity-dependent nanoscale swelling, which potentially serves to dynamically tune the transmission speed of neural information.
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Affiliation(s)
- Junhwan Kwon
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
| | - Sungho Lee
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, The Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
| | - Yongjae Jo
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
| | - Myunghwan Choi
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, The Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
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29
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Schwann cell functions in peripheral nerve development and repair. Neurobiol Dis 2023; 176:105952. [PMID: 36493976 DOI: 10.1016/j.nbd.2022.105952] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
The glial cell of the peripheral nervous system (PNS), the Schwann cell (SC), counts among the most multifaceted cells of the body. During development, SCs secure neuronal survival and participate in axonal path finding. Simultaneously, they orchestrate the architectural set up of the developing nerves, including the blood vessels and the endo-, peri- and epineurial layers. Perinatally, in rodents, SCs radially sort and subsequently myelinate individual axons larger than 1 μm in diameter, while small calibre axons become organised in non-myelinating Remak bundles. SCs have a vital role in maintaining axonal health throughout life and several specialized SC types perform essential functions at specific locations, such as terminal SC at the neuromuscular junction (NMJ) or SC within cutaneous sensory end organs. In addition, neural crest derived satellite glia maintain a tight communication with the soma of sensory, sympathetic, and parasympathetic neurons and neural crest derivatives are furthermore an indispensable part of the enteric nervous system. The remarkable plasticity of SCs becomes evident in the context of a nerve injury, where SC transdifferentiate into intriguing repair cells, which orchestrate a regenerative response that promotes nerve repair. Indeed, the multiple adaptations of SCs are captivating, but remain often ill-resolved on the molecular level. Here, we summarize and discuss the knowns and unknowns of the vast array of functions that this single cell type can cover in peripheral nervous system development, maintenance, and repair.
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30
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van den Bosch AMR, Hümmert S, Steyer A, Ruhwedel T, Hamann J, Smolders J, Nave KA, Stadelmann C, Kole MHP, Möbius W, Huitinga I. Ultrastructural Axon-Myelin Unit Alterations in Multiple Sclerosis Correlate with Inflammation. Ann Neurol 2022; 93:856-870. [PMID: 36565265 DOI: 10.1002/ana.26585] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Changes in the normal-appearing white matter (NAWM) in multiple sclerosis (MS) may contribute to disease progression. Here, we systematically quantified ultrastructural and subcellular characteristics of the axon-myelin unit in MS NAWM and determined how this correlates with low-grade inflammation. METHODS Human brain tissue obtained with short postmortem delay and fixation at autopsy enables systematic quantification of ultrastructural characteristics. In this study, we performed high-resolution immunohis tochemistry and quantitative transmission electron microscopy to study inflammation and ultrastructural characteristics of the axon-myelin unit in MS NAWM (n = 8) and control white matter (WM) in the optic nerve. RESULTS In the MS NAWM, there were more activated and phagocytic microglia cells (HLA+ P2RY12- and Iba1+ CD68+ ) and more T cells (CD3+ ) compared to control WM, mainly located in the perivascular space. In MS NAWM compared to control WM, there were, as expected, longer paranodes and juxtaparanodes and larger overlap between paranodes and juxtaparanodes. There was less compact myelin wrapping, a lower g-ratio, and a higher frequency of axonal mitochondria. Changes in myelin and axonal mitochondrial frequency correlated positively with the number of active and phagocytic microglia and lymphocytes in the optic nerve. INTERPRETATION These data suggest that in MS NAWM myelin detachment and uncompact myelin wrapping occurs, potassium channels are unmasked at the nodes of Ranvier, and axonal energy demand is increased, or mitochondrial transport is stagnated, accompanied by increased presence of activated and phagocytic microglia and T cells. These subclinical alterations to the axon-myelin unit in MS NAWM may contribute to disease progression. ANN NEUROL 2023.
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Affiliation(s)
- Aletta M R van den Bosch
- Department of Neuroimmunology, Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences, Amsterdam, the Netherlands
| | - Sophie Hümmert
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Anna Steyer
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Jörg Hamann
- Department of Neuroimmunology, Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences, Amsterdam, the Netherlands.,Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Joost Smolders
- Department of Neuroimmunology, Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences, Amsterdam, the Netherlands.,Department of Neurology and Immunology, Multiple Sclerosis Center ErasMS, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Christine Stadelmann
- Department of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Maarten H P Kole
- Department of Axonal Signaling, Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences, Amsterdam, the Netherlands.,Cell Biology, Neurobiology, and Biophysics, Department of Biology, Faculty of Science, University of Utrecht, Utrecht, the Netherlands
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Inge Huitinga
- Department of Neuroimmunology, Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences, Amsterdam, the Netherlands.,Center for Neuroscience, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, the Netherlands
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31
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Kole K, Voesenek BJB, Brinia ME, Petersen N, Kole MHP. Parvalbumin basket cell myelination accumulates axonal mitochondria to internodes. Nat Commun 2022; 13:7598. [PMID: 36494349 PMCID: PMC9734141 DOI: 10.1038/s41467-022-35350-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
Parvalbumin-expressing (PV+) basket cells are fast-spiking inhibitory interneurons that exert critical control over local circuit activity and oscillations. PV+ axons are often myelinated, but the electrical and metabolic roles of interneuron myelination remain poorly understood. Here, we developed viral constructs allowing cell type-specific investigation of mitochondria with genetically encoded fluorescent probes. Single-cell reconstructions revealed that mitochondria selectively cluster to myelinated segments of PV+ basket cells, confirmed by analyses of a high-resolution electron microscopy dataset. In contrast to the increased mitochondrial densities in excitatory axons cuprizone-induced demyelination abolished mitochondrial clustering in PV+ axons. Furthermore, with genetic deletion of myelin basic protein the mitochondrial clustering was still observed at internodes wrapped by noncompacted myelin, indicating that compaction is dispensable. Finally, two-photon imaging of action potential-evoked calcium (Ca2+) responses showed that interneuron myelination attenuates both the cytosolic and mitochondrial Ca2+ transients. These findings suggest that oligodendrocyte ensheathment of PV+ axons assembles mitochondria to branch selectively fine-tune metabolic demands.
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Affiliation(s)
- Koen Kole
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Bas J. B. Voesenek
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Maria E. Brinia
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands ,grid.5216.00000 0001 2155 0800Medical School, National Kapodistrian University of Athens, Athens, 11527 Greece
| | - Naomi Petersen
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Maarten H. P. Kole
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands ,grid.5477.10000000120346234Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
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32
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Fan S, Qi L, Li J, Liu S, Li R, Zhan T, Li X, Wu D, Lau P, Qiu B, Bi G, Ding W. Accelerating Neurite Growth and Directing Neuronal Connections Constrained by 3D Porous Microtubes. NANO LETTERS 2022; 22:8991-8999. [PMID: 36327196 DOI: 10.1021/acs.nanolett.2c03232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Investigation of neural growth and connection is crucial in the field of neural tissue engineering. Here, using a femtosecond laser direct writing (fs-DLW) technique, we propose a directionally aligned porous microtube array as a culture system for accelerating the growth of neurons and directing the connection of neurites. These microtubes exhibited an unprecedented guidance effect toward the outgrowth of primary embryonic rat hippocampal neurons, with a wrap resembling the myelin sheaths of neurons. The speed of neurite growth inside these microtubes was significantly faster than that outside these microtubes. We also achieved selective/directing connection of neural networks inside the magnetic microtubes via precise microtube delivery to a gap between two neural clusters. This work not only proposes a powerful microtube platform for accelerated growth of neurons but also offers a new idea for constructing biological neural circuits by arranging the size, location, and pattern of microtubes.
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Affiliation(s)
- Shengying Fan
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Lei Qi
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230026, China
| | - Jiawen Li
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shunli Liu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Rui Li
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tongzhou Zhan
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaowei Li
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dong Wu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Pakming Lau
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230026, China
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bensheng Qiu
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guoqiang Bi
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Weiping Ding
- Department of Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
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Chataigner LMP, Gogou C, den Boer MA, Frias CP, Thies-Weesie DME, Granneman JCM, Heck AJR, Meijer DH, Janssen BJC. Structural insights into the contactin 1 - neurofascin 155 adhesion complex. Nat Commun 2022; 13:6607. [PMID: 36329006 PMCID: PMC9633819 DOI: 10.1038/s41467-022-34302-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
Cell-surface expressed contactin 1 and neurofascin 155 control wiring of the nervous system and interact across cells to form and maintain paranodal myelin-axon junctions. The molecular mechanism of contactin 1 - neurofascin 155 adhesion complex formation is unresolved. Crystallographic structures of complexed and individual contactin 1 and neurofascin 155 binding regions presented here, provide a rich picture of how competing and complementary interfaces, post-translational glycosylation, splice differences and structural plasticity enable formation of diverse adhesion sites. Structural, biophysical, and cell-clustering analysis reveal how conserved Ig1-2 interfaces form competing heterophilic contactin 1 - neurofascin 155 and homophilic neurofascin 155 complexes whereas contactin 1 forms low-affinity clusters through interfaces on Ig3-6. The structures explain how the heterophilic Ig1-Ig4 horseshoe's in the contactin 1 - neurofascin 155 complex define the 7.4 nm paranodal spacing and how the remaining six domains enable bridging of distinct intercellular distances.
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Affiliation(s)
- Lucas M. P. Chataigner
- grid.5477.10000000120346234Structural Biochemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Christos Gogou
- grid.5292.c0000 0001 2097 4740Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Maurits A. den Boer
- grid.5477.10000000120346234Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Cátia P. Frias
- grid.5292.c0000 0001 2097 4740Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Dominique M. E. Thies-Weesie
- grid.5477.10000000120346234Van’t Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute of Nanomaterials Science, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Joke C. M. Granneman
- grid.5477.10000000120346234Structural Biochemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Albert J. R. Heck
- grid.5477.10000000120346234Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Dimphna H. Meijer
- grid.5292.c0000 0001 2097 4740Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Bert J. C. Janssen
- grid.5477.10000000120346234Structural Biochemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
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34
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Spatio-temporal modeling of saltatory conduction in neurons using Poisson-Nernst–Planck treatment and estimation of conduction velocity. BRAIN MULTIPHYSICS 2022. [DOI: 10.1016/j.brain.2022.100061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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35
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Oligodendroglia are emerging players in several forms of learning and memory. Commun Biol 2022; 5:1148. [PMID: 36309567 PMCID: PMC9617857 DOI: 10.1038/s42003-022-04116-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 10/14/2022] [Indexed: 11/15/2022] Open
Abstract
Synaptic plasticity is the fundamental cellular mechanism of learning and memory, but recent research reveals that myelin-forming glia, oligodendrocytes (OL), are also involved. They contribute in ways that synaptic plasticity cannot, and the findings have not been integrated into the established conceptual framework used in the field of learning and memory. OLs and their progenitors are involved in long-term memory, memory consolidation, working memory, and recall in associative learning. They also contribute to short-term memory and non-associative learning by affecting synaptic transmission, intrinsic excitability of axons, and neural oscillations. Oligodendroglial involvement expands the field beyond synaptic plasticity to system-wide network function, where precise spike time arrival and neural oscillations are critical in information processing, storage, and retrieval. A Perspective highlights current evidence that supports oligodendrocytes and their progenitors’ involvement in cognition and proposes that our understanding of learning and memory can be expanded beyond the classic view of synaptic plasticity to a system-wide network function.
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36
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Bacmeister CM, Huang R, Osso LA, Thornton MA, Conant L, Chavez AR, Poleg-Polsky A, Hughes EG. Motor learning drives dynamic patterns of intermittent myelination on learning-activated axons. Nat Neurosci 2022; 25:1300-1313. [PMID: 36180791 PMCID: PMC9651929 DOI: 10.1038/s41593-022-01169-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 08/18/2022] [Indexed: 01/10/2023]
Abstract
Myelin plasticity occurs when newly formed and pre-existing oligodendrocytes remodel existing patterns of myelination. Myelin remodeling occurs in response to changes in neuronal activity and is required for learning and memory. However, the link between behavior-induced neuronal activity and circuit-specific changes in myelination remains unclear. Using longitudinal in vivo two-photon imaging and targeted labeling of learning-activated neurons in mice, we explore how the pattern of intermittent myelination is altered on individual cortical axons during learning of a dexterous reach task. We show that behavior-induced myelin plasticity is targeted to learning-activated axons and occurs in a staged response across cortical layers in the mouse primary motor cortex. During learning, myelin sheaths retract, which results in lengthening of nodes of Ranvier. Following motor learning, addition of newly formed myelin sheaths increases the number of continuous stretches of myelination. Computational modeling suggests that motor learning-induced myelin plasticity initially slows and subsequently increases axonal conduction speed. Finally, we show that both the magnitude and timing of nodal and myelin dynamics correlate with improvement of behavioral performance during motor learning. Thus, learning-induced and circuit-specific myelination changes may contribute to information encoding in neural circuits during motor learning.
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Affiliation(s)
- Clara M Bacmeister
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
- Neuroscience IDP Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Rongchen Huang
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO, USA
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Lindsay A Osso
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael A Thornton
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Lauren Conant
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anthony R Chavez
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Alon Poleg-Polsky
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ethan G Hughes
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA.
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37
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Hari K, Lucas-Osma AM, Metz K, Lin S, Pardell N, Roszko DA, Black S, Minarik A, Singla R, Stephens MJ, Pearce RA, Fouad K, Jones KE, Gorassini MA, Fenrich KK, Li Y, Bennett DJ. GABA facilitates spike propagation through branch points of sensory axons in the spinal cord. Nat Neurosci 2022; 25:1288-1299. [PMID: 36163283 PMCID: PMC10042549 DOI: 10.1038/s41593-022-01162-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 08/11/2022] [Indexed: 11/09/2022]
Abstract
Movement and posture depend on sensory feedback that is regulated by specialized GABAergic neurons (GAD2+) that form axo-axonic contacts onto myelinated proprioceptive sensory axons and are thought to be inhibitory. However, we report here that activating GAD2+ neurons directly with optogenetics or indirectly by cutaneous stimulation actually facilitates sensory feedback to motor neurons in rodents and humans. GABAA receptors located at or near nodes of Ranvier of sensory axons cause this facilitation by preventing spike propagation failure at the many axon branch points, which is otherwise common without GABA. In contrast, GABAA receptors are generally lacking from axon terminals and so cannot inhibit transmitter release onto motor neurons, unlike GABAB receptors that cause presynaptic inhibition. GABAergic innervation near nodes and branch points allows individual branches to function autonomously, with GAD2+ neurons regulating which branches conduct, adding a computational layer to the neuronal networks generating movement and likely generalizing to other central nervous system axons.
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Affiliation(s)
- Krishnapriya Hari
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Ana M Lucas-Osma
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Krista Metz
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Shihao Lin
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Noah Pardell
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - David A Roszko
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Sophie Black
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Anna Minarik
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Rahul Singla
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Marilee J Stephens
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Robert A Pearce
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Karim Fouad
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Kelvin E Jones
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Faculty of Kinesiology, Sport and Recreation, University of Alberta, Edmonton, AB, Canada
| | - Monica A Gorassini
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Keith K Fenrich
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Yaqing Li
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Cell Biology, Emory University, Atlanta, GA, USA
| | - David J Bennett
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada. .,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada.
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Zhang Y, Shen B, Wu T, Zhao J, Jing JC, Wang P, Sasaki-Capela K, Dunphy WG, Garrett D, Maslov K, Wang W, Wang LV. Ultrafast and hypersensitive phase imaging of propagating internodal current flows in myelinated axons and electromagnetic pulses in dielectrics. Nat Commun 2022; 13:5247. [PMID: 36068212 PMCID: PMC9448739 DOI: 10.1038/s41467-022-33002-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 08/25/2022] [Indexed: 12/30/2022] Open
Abstract
Many ultrafast phenomena in biology and physics are fundamental to our scientific understanding but have not yet been visualized owing to the extreme speed and sensitivity requirements in imaging modalities. Two examples are the propagation of passive current flows through myelinated axons and electromagnetic pulses through dielectrics, which are both key to information processing in living organisms and electronic devices. Here, we demonstrate differentially enhanced compressed ultrafast photography (Diff-CUP) to directly visualize propagations of passive current flows at approximately 100 m/s along internodes, i.e., continuous myelinated axons between nodes of Ranvier, from Xenopus laevis sciatic nerves and of electromagnetic pulses at approximately 5 × 107 m/s through lithium niobate. The spatiotemporal dynamics of both propagation processes are consistent with the results from computational models, demonstrating that Diff-CUP can span these two extreme timescales while maintaining high phase sensitivity. With its ultrahigh speed (picosecond resolution), high sensitivity, and noninvasiveness, Diff-CUP provides a powerful tool for investigating ultrafast biological and physical phenomena.
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Affiliation(s)
- Yide Zhang
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Binglin Shen
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
- Key Laboratory of Optoelectronic Devices and Systems of Guangdong Province and Ministry of Education, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Tong Wu
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
- Key Laboratory of Space Photoelectric Detection and Perception, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Jerry Zhao
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Joseph C Jing
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Peng Wang
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Kanomi Sasaki-Capela
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - William G Dunphy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - David Garrett
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Konstantin Maslov
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Weiwei Wang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lihong V Wang
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
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Al-Zikri PNH, Huat TJ, Khan AA, Patar A, Reza MF, Idris FM, Abdullah JM, Jaafar H. Transplantation of IGF-1-induced BMSC-derived NPCs promotes tissue repair and motor recovery in a rat spinal cord injury model. Heliyon 2022; 8:e10384. [PMID: 36090221 PMCID: PMC9449758 DOI: 10.1016/j.heliyon.2022.e10384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/14/2022] [Accepted: 08/15/2022] [Indexed: 12/02/2022] Open
Abstract
Bone marrow-derived mesenchymal stem cells (BMSCs) have therapeutic potential for spinal cord injury (SCI). We have shown that insulin-like growth factor 1 (IGF-1) enhances the cellular proliferation and survivability of BMSCs-derived neural progenitor cells (NPCs) by downregulating miR-22-3p. However, the functional application of BMSCs-derived NPCs has not been investigated fully. In this study, we demonstrate that knockdown of endogenous miR-22-3p in BMSCs-derived NPCs upregulates Akt1 expression, leading to enhanced cellular proliferation. RNASeq analysis reveals 3,513 differentially expressed genes in NPCs. The upregulated genes in NPCs enrich the gene ontology term associated with nervous system development. Terminally differentiated NPCs generate cells with neuronal-like morphology and phenotypes. Transplantation of NPCs in the SCI rat model results in better recovery in locomotor and sensory functions 4 weeks after transplantation. Altogether, the result of this study demonstrate that NPCs derived with IGF-1 supplementation could be differentiated into functional neural lineage cells and are optimal for stem cell therapy in SCI.
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40
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Zeng H, Zhang Y, Ma Y, Li S. Electromagnetic modeling and simulation of the biophoton propagation in myelinated axon waveguide. APPLIED OPTICS 2022; 61:4013-4021. [PMID: 36256074 DOI: 10.1364/ao.446845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/21/2022] [Indexed: 06/16/2023]
Abstract
Biophotons in the nervous system are a potential carrier of neural signals. Previous experiments and studies indicated that biophotons are closely related to the neuronal activity and can propagate along myelinated axons. We establish a multilayer electromagnetic simulation model and demonstrate that the myelinated axon waveguide has low attenuation and low dispersion and operates in a narrow bandwidth on the order of 10 nm. We also find that the operating wavelength of the waveguide is almost linearly related to the axon diameter and the number of myelin layers. Each additional layer of the myelin sheath causes the operating wavelength of the myelinated axon waveguide to shift 52.3 nm to the long-wave direction, while an increase in the axon diameter of 1.0 µm causes the operating wavelength to shift 94.5 nm to the short-wave direction. These findings well explain the tendency of the spectral redshift among different species and the spectral blueshift during the aging process of mice. Via the analysis method in this paper, we can predict the wavelength of the propagating biophotons based on the neural structure.
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41
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Radomski KL, Zi X, Lischka FW, Noble MD, Galdzicki Z, Armstrong RC. Acute axon damage and demyelination are mitigated by 4-aminopyridine (4-AP) therapy after experimental traumatic brain injury. Acta Neuropathol Commun 2022; 10:67. [PMID: 35501931 PMCID: PMC9059462 DOI: 10.1186/s40478-022-01366-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/11/2022] [Indexed: 11/10/2022] Open
Abstract
Damage to long axons in white matter tracts is a major pathology in closed head traumatic brain injury (TBI). Acute TBI treatments are needed that protect against axon damage and promote recovery of axon function to prevent long term symptoms and neurodegeneration. Our prior characterization of axon damage and demyelination after TBI led us to examine repurposing of 4-aminopyridine (4-AP), an FDA-approved inhibitor of voltage-gated potassium (Kv) channels. 4-AP is currently indicated to provide symptomatic relief for patients with chronic stage multiple sclerosis, which involves axon damage and demyelination. We tested clinically relevant dosage of 4-AP as an acute treatment for experimental TBI and found multiple benefits in corpus callosum axons. This randomized, controlled pre-clinical study focused on the first week after TBI, when axons are particularly vulnerable. 4-AP treatment initiated one day post-injury dramatically reduced axon damage detected by intra-axonal fluorescence accumulations in Thy1-YFP mice of both sexes. Detailed electron microscopy in C57BL/6 mice showed that 4-AP reduced pathological features of mitochondrial swelling, cytoskeletal disruption, and demyelination at 7 days post-injury. Furthermore, 4-AP improved the molecular organization of axon nodal regions by restoring disrupted paranode domains and reducing Kv1.2 channel dispersion. 4-AP treatment did not resolve deficits in action potential conduction across the corpus callosum, based on ex vivo electrophysiological recordings at 7 days post-TBI. Thus, this first study of 4-AP effects on axon damage in the acute period demonstrates a significant decrease in multiple pathological hallmarks of axon damage after experimental TBI.
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Affiliation(s)
- Kryslaine L. Radomski
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Xiaomei Zi
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Fritz W. Lischka
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Biomedical Instrumentation Center, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Mark D. Noble
- Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Ave, Box 633, Rochester, NY 14642 USA
| | - Zygmunt Galdzicki
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Regina C. Armstrong
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
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42
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Chen SQ, Chen XY, Cui YZ, Yan BX, Zhou Y, Wang ZY, Xu F, Huang YZ, Zheng YX, Man XY. Cutaneous nerve fibers participate in the progression of psoriasis by linking epidermal keratinocytes and immunocytes. Cell Mol Life Sci 2022; 79:267. [PMID: 35488965 PMCID: PMC11072315 DOI: 10.1007/s00018-022-04299-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 03/23/2022] [Accepted: 04/08/2022] [Indexed: 12/11/2022]
Abstract
Recent studies have illustrated that psoriatic lesions are innervated by dense sensory nerve fibers. Psoriatic plaques appeared to improve after central or peripheral nerve injury. Therefore, the nervous system may play a vital role in psoriasis. We aimed to clarify the expression of nerve fibers in psoriasis and their relationship with immune cells and keratinocytes, and to explore the effect of skin nerve impairment. Our results illustrated that nerve fibers in psoriatic lesions increased and were closely innervated around immune cells and keratinocytes. RNA-seq analysis showed that peripheral sensory nerve-related genes were disrupted in psoriasis. In spinal cord hemi-section mice, sensory impairment improved psoriasiform dermatitis and inhibited the abnormal proliferation of keratinocytes. Botulinum toxin A alleviated psoriasiform dermatitis by inhibiting the secretion of calcitonin gene-related peptide. Collectively, cutaneous nerve fibers participate in the progression of psoriasis by linking epidermal keratinocytes and immunocytes. Neurological intervention may be a new treatment strategy for psoriasis.
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Affiliation(s)
- Si-Qi Chen
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Xue-Yan Chen
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Ying-Zhe Cui
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Bing-Xi Yan
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Yuan Zhou
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Zhao-Yuan Wang
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Fan Xu
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Yan-Zhou Huang
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Yu-Xin Zheng
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China
| | - Xiao-Yong Man
- Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, #88 Jiefang Road, Hangzhou, China.
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43
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Shimba K, Asahina T, Sakai K, Kotani K, Jimbo Y. Recording Saltatory Conduction Along Sensory Axons Using a High-Density Microelectrode Array. Front Neurosci 2022; 16:854637. [PMID: 35509449 PMCID: PMC9058065 DOI: 10.3389/fnins.2022.854637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/25/2022] [Indexed: 11/13/2022] Open
Abstract
Myelinated fibers are specialized neurological structures used for conducting action potentials quickly and reliably, thus assisting neural functions. Although demyelination leads to serious functional impairments, little is known the relationship between myelin structural change and increase in conduction velocity during myelination and demyelination processes. There are no appropriate methods for the long-term evaluation of spatial characteristics of saltatory conduction along myelinated axons. Herein, we aimed to detect saltatory conduction from the peripheral nervous system neurons using a high-density microelectrode array. Rat sensory neurons and intrinsic Schwann cells were cultured. Immunofluorescence and ultrastructure examination showed that the myelinating Schwann cells appeared at 1 month, and compact myelin was formed by 10 weeks in vitro. Activity of rat sensory neurons was evoked with optogenetic stimulation, and axon conduction was detected with high-density microelectrode arrays. Some conductions included high-speed segments with low signal amplitude. The same segment could be detected with electrical recording and immunofluorescent imaging for a myelin-related protein. The spatiotemporal analysis showed that some segments show a velocity of more than 2 m/s and that ends of the segments show a higher electrical sink, suggesting that saltatory conduction occurred in myelinated axons. Moreover, mathematical modeling supported that the recorded signal was in the appropriate range for axon and electrode sizes. Overall, our method could be a feasible tool for evaluating spatial characteristics of axon conduction including saltatory conduction, which is applicable for studying demyelination and remyelination.
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Affiliation(s)
- Kenta Shimba
- Department of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
- *Correspondence: Kenta Shimba, , orcid.org/0000-0003-1156-260X
| | - Takahiro Asahina
- Department of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
- Japan Society for Promotion of Science, Tokyo, Japan
| | - Koji Sakai
- Department of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Kiyoshi Kotani
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Yasuhiko Jimbo
- Department of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
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44
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Buscham TJ, Eichel-Vogel MA, Steyer AM, Jahn O, Strenzke N, Dardawal R, Memhave TR, Siems SB, Müller C, Meschkat M, Sun T, Ruhwedel T, Möbius W, Krämer-Albers EM, Boretius S, Nave KA, Werner HB. Progressive axonopathy when oligodendrocytes lack the myelin protein CMTM5. eLife 2022; 11:75523. [PMID: 35274615 PMCID: PMC8916772 DOI: 10.7554/elife.75523] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/27/2022] [Indexed: 11/26/2022] Open
Abstract
Oligodendrocytes facilitate rapid impulse propagation along the axons they myelinate and support their long-term integrity. However, the functional relevance of many myelin proteins has remained unknown. Here, we find that expression of the tetraspan-transmembrane protein CMTM5 (chemokine-like factor-like MARVEL-transmembrane domain containing protein 5) is highly enriched in oligodendrocytes and central nervous system (CNS) myelin. Genetic disruption of the Cmtm5 gene in oligodendrocytes of mice does not impair the development or ultrastructure of CNS myelin. However, oligodendroglial Cmtm5 deficiency causes an early-onset progressive axonopathy, which we also observe in global and tamoxifen-induced oligodendroglial Cmtm5 mutants. Presence of the WldS mutation ameliorates the axonopathy, implying a Wallerian degeneration-like pathomechanism. These results indicate that CMTM5 is involved in the function of oligodendrocytes to maintain axonal integrity rather than myelin biogenesis.
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Affiliation(s)
- Tobias J Buscham
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Maria A Eichel-Vogel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Anna M Steyer
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - Nicola Strenzke
- Institute for Auditory Neuroscience, University Medicine Göttingen, Göttingen, Germany
| | - Rakshit Dardawal
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Tor R Memhave
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Sophie B Siems
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Christina Müller
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany
| | - Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Abberior Instruments Gmbh, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany
| | - Susann Boretius
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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45
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Ben-Shalom R, Ladd A, Artherya NS, Cross C, Kim KG, Sanghevi H, Korngreen A, Bouchard KE, Bender KJ. NeuroGPU: Accelerating multi-compartment, biophysically detailed neuron simulations on GPUs. J Neurosci Methods 2022; 366:109400. [PMID: 34728257 PMCID: PMC9887806 DOI: 10.1016/j.jneumeth.2021.109400] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 10/09/2021] [Accepted: 10/27/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND The membrane potential of individual neurons depends on a large number of interacting biophysical processes operating on spatial-temporal scales spanning several orders of magnitude. The multi-scale nature of these processes dictates that accurate prediction of membrane potentials in specific neurons requires the utilization of detailed simulations. Unfortunately, constraining parameters within biologically detailed neuron models can be difficult, leading to poor model fits. This obstacle can be overcome partially by numerical optimization or detailed exploration of parameter space. However, these processes, which currently rely on central processing unit (CPU) computation, often incur orders of magnitude increases in computing time for marginal improvements in model behavior. As a result, model quality is often compromised to accommodate compute resources. NEW METHOD Here, we present a simulation environment, NeuroGPU, that takes advantage of the inherent parallelized structure of the graphics processing unit (GPU) to accelerate neuronal simulation. RESULTS & COMPARISON WITH EXISTING METHODS NeuroGPU can simulate most biologically detailed models 10-200 times faster than NEURON simulation running on a single core and 5 times faster than GPU simulators (CoreNEURON). NeuroGPU is designed for model parameter tuning and best performs when the GPU is fully utilized by running multiple (> 100) instances of the same model with different parameters. When using multiple GPUs, NeuroGPU can reach to a speed-up of 800 fold compared to single core simulations, especially when simulating the same model morphology with different parameters. We demonstrate the power of NeuoGPU through large-scale parameter exploration to reveal the response landscape of a neuron. Finally, we accelerate numerical optimization of biophysically detailed neuron models to achieve highly accurate fitting of models to simulation and experimental data. CONCLUSIONS Thus, NeuroGPU is the fastest available platform that enables rapid simulation of multi-compartment, biophysically detailed neuron models on commonly used computing systems accessible by many scientists.
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Affiliation(s)
- Roy Ben-Shalom
- Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States; Department of Neurology, University of California, San Francisco, San Francisco, CA, United States; MIND Institute University of California, Davis, CA, United States; Computational Research Division, Lawrence Berkeley National Lab, Berkeley, CA, United States.
| | - Alexander Ladd
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, United States
| | - Nikhil S Artherya
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, United States
| | - Christopher Cross
- Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States
| | - Kyung Geun Kim
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, United States
| | - Hersh Sanghevi
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, United States
| | - Alon Korngreen
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Kristofer E Bouchard
- Computational Research Division, Lawrence Berkeley National Lab, Berkeley, CA, United States; Hellen Wills Neuroscience Institute & Redwood Center for Theoretical Neuroscience, University of California, Berkeley, Berkeley, CA, United States; Biological Systems and Engineering Division, Lawrence Berkeley National Lab, Berkeley, CA, United States
| | - Kevin J Bender
- Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States; Department of Neurology, University of California, San Francisco, San Francisco, CA, United States.
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46
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Dubey M, Pascual-Garcia M, Helmes K, Wever DD, Hamada MS, Kushner SA, Kole MHP. Myelination synchronizes cortical oscillations by consolidating parvalbumin-mediated phasic inhibition. eLife 2022; 11:73827. [PMID: 35001871 PMCID: PMC8887893 DOI: 10.7554/elife.73827] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/28/2021] [Indexed: 12/18/2022] Open
Abstract
Parvalbumin-positive (PV+) γ-aminobutyric acid (GABA) interneurons are critically involved in producing rapid network oscillations and cortical microcircuit computations, but the significance of PV+ axon myelination to the temporal features of inhibition remains elusive. Here, using toxic and genetic mouse models of demyelination and dysmyelination, respectively, we find that loss of compact myelin reduces PV+ interneuron presynaptic terminals and increases failures, and the weak phasic inhibition of pyramidal neurons abolishes optogenetically driven gamma oscillations in vivo. Strikingly, during behaviors of quiet wakefulness selectively theta rhythms are amplified and accompanied by highly synchronized interictal epileptic discharges. In support of a causal role of impaired PV-mediated inhibition, optogenetic activation of myelin-deficient PV+ interneurons attenuated the power of slow theta rhythms and limited interictal spike occurrence. Thus, myelination of PV axons is required to consolidate fast inhibition of pyramidal neurons and enable behavioral state-dependent modulation of local circuit synchronization.
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Affiliation(s)
- Mohit Dubey
- Department of Axonal Signaling, Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
| | | | - Koke Helmes
- Department of Axonal Signaling, Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
| | - Dennis D Wever
- Department of Axonal Signaling, Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
| | - Mustafa S Hamada
- Department of Axonal Signaling, Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands.,Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Steven A Kushner
- Department of Psychiatry, Erasmus Medical Centre, Rotterdam, Netherlands
| | - Maarten H P Kole
- Department of Axonal Signaling, Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands.,Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
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47
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Adonias GL, Duffy C, Barros MT, McCoy CE, Balasubramaniam S. Analysis of the Information Capacity of Neuronal Molecular Communications under Demyelination and Remyelination. IEEE Trans Neural Syst Rehabil Eng 2021; 29:2765-2774. [PMID: 34932481 DOI: 10.1109/tnsre.2021.3137350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Demyelination of neurons can compromise the communication performance between the cells as the absence of myelin attenuates the action potential propagated through the axonal pathway. In this work, we propose a hybrid experimental and simulation model for analyzing the demyelination effects on neuron communication. The experiment involves locally induced demyelination using Lysolecithin and from this, a myelination index is empirically estimated from analysis of cell images. This index is then coupled with a modified Hodgkin-Huxley computational model to simulate the resulting impact that the de/myelination processes has on the signal propagation along the axon. The effects of signal degradation and transfer of neuronal information are simulated and quantified at multiple levels, and this includes (1) compartment per compartment of a single neuron, (2) bipartite synapse and the effects on the excitatory post-synaptic potential, and (3) a small network of neurons to understand how the impact of de/myelination has on the whole network. By using the myelination index in the simulation model, we can determine the level of attenuation of the action potential concerning the myelin quantity, as well as the analysis of internal signalling functions of the neurons and their impact on the overall spike firing rate. We believe that this hybrid experimental and in silico simulation model can result in a new analysis tool that can predict the gravity of the degeneration through the estimation of the spiking activity and vice-versa, which can minimize the need for specialised laboratory equipment needed for single-cell communication analysis.
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48
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Gao Y, Kong L, Liu S, Liu K, Zhu J. Impact of Neurofascin on Chronic Inflammatory Demyelinating Polyneuropathy via Changing the Node of Ranvier Function: A Review. Front Mol Neurosci 2021; 14:779385. [PMID: 34975399 PMCID: PMC8716720 DOI: 10.3389/fnmol.2021.779385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022] Open
Abstract
The effective conduction of action potential in the peripheral nervous system depends on the structural and functional integrity of the node of Ranvier and paranode. Neurofascin (NF) plays an important role in the conduction of action potential in a saltatory manner. Two subtypes of NF, NF186, and NF155, are involved in the structure of the node of Ranvier. In patients with chronic inflammatory demyelinating polyneuropathy (CIDP), anti-NF antibodies are produced when immunomodulatory dysfunction occurs, which interferes with the conduction of action potential and is considered the main pathogenic factor of CIDP. In this study, we describe the assembling mechanism and anatomical structure of the node of Ranvier and the necessary cell adhesion molecules for its physiological function. The main points of this study are that we summarized the recent studies on the role of anti-NF antibodies in the changes in the node of Ranvier function and its impact on clinical manifestations and analyzed the possible mechanisms underlying the pathogenesis of CIDP.
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Affiliation(s)
- Ying Gao
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Lingxin Kong
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Shan Liu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Kangding Liu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Jie Zhu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
- Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
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49
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Sajedi S, Fellner A, Werginz P, Rattay F. Block Phenomena During Electric Micro-Stimulation of Pyramidal Cells and Retinal Ganglion Cells. Front Cell Neurosci 2021; 15:771600. [PMID: 34899192 PMCID: PMC8663762 DOI: 10.3389/fncel.2021.771600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
Electric micro-stimulation of the nervous system is a means to restore various body functions. The stimulus amplitude necessary to generate action potentials, the lower threshold (LT), is well characterized for many neuronal populations. However, electric overstimulation above an upper threshold (UT) prevents action potential generation and therefore hinders optimal neuro-rehabilitation. Previous studies demonstrated the impact of the UT in micro-stimulation of retinal ganglion cells (RGCs). The observed phenomenon is mostly explained by (i) reversed sodium ion flow in the soma membrane, and (ii) anodal surround block that hinders spike conduction in strongly hyperpolarized regions of the axon at high stimulus intensities. However, up to now, no detailed study of the nature of these phenomena has been presented, particularly for different cell types. Here, we present computational analyses of LT and UT for layer 5 pyramidal cells (PCs) as well as alpha RGCs. Model neurons were stimulated in close vicinity to the cell body and LTs and UTs as well as the ratio UT/LT were compared. Aside from a simple point source electrode and monophasic stimuli also realistic electrode and pulse configurations were examined. The analysis showed: (i) in RGCs, the soma contributed to action potential initiation and block for small electrode distances, whereas in PCs the soma played no role in LTs or UTs. (ii) In both cell types, action potential always initiated within the axon initial segment at LT. (iii) In contrast to a complete block of spike conductance at UT that occurred in RGCs, an incomplete block of spiking appeared in PC axon collaterals. (iv) PC axon collateral arrangement influenced UTs but had small impact on LTs. (v) Population responses of RGCs change from circular regions of activation to ring-shaped patterns for increasing stimulus amplitude. A better understanding of the stimulation window that can reliably activate target neurons will benefit the future development of neuroprostheses.
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Affiliation(s)
- Sogand Sajedi
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Andreas Fellner
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Paul Werginz
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Frank Rattay
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
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50
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Edgar JM, McGowan E, Chapple KJ, Möbius W, Lemgruber L, Insall RH, Nave K, Boullerne A. Río-Hortega's drawings revisited with fluorescent protein defines a cytoplasm-filled channel system of CNS myelin. J Anat 2021; 239:1241-1255. [PMID: 34713444 PMCID: PMC8602028 DOI: 10.1111/joa.13577] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 01/13/2023] Open
Abstract
A century ago this year, Pío del Río-Hortega (1921) coined the term 'oligodendroglia' for the 'interfascicular glia' with very few processes, launching an extensive discovery effort on his new cell type. One hundred years later, we review his original contributions to our understanding of the system of cytoplasmic channels within myelin in the context of what we observe today using light and electron microscopy of genetically encoded fluorescent reporters and immunostaining. We use the term myelinic channel system to describe the cytoplasm-delimited spaces associated with myelin; being the paranodal loops, inner and outer tongues, cytoplasm-filled spaces through compact myelin and further complex motifs associated to the sheath. Using a central nervous system myelinating cell culture model that contains all major neural cell types and produces compact myelin, we find that td-tomato fluorescent protein delineates the myelinic channel system in a manner reminiscent of the drawings of adult white matter by Río-Hortega, despite that he questioned whether some cytoplasmic figures he observed represented artefact. Together, these data lead us to propose a slightly revised model of the 'unrolled' sheath. Further, we show that the myelinic channel system, while relatively stable, can undergo subtle dynamic shape changes over days. Importantly, we capture an under-appreciated complexity of the myelinic channel system in mature myelin sheaths.
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Affiliation(s)
- Julia M. Edgar
- Axo‐Glial GroupInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
- Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Eleanor McGowan
- Axo‐Glial GroupInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Katie J. Chapple
- Axo‐Glial GroupInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Wiebke Möbius
- Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
- Electron Microscopy Core UnitMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Leandro Lemgruber
- Glasgow Imaging FacilityInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | | | - Klaus‐Armin Nave
- Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Anne Boullerne
- Department of AnesthesiologyUniversity of Illinois at ChicagoChicagoIllinoisUSA
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