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Lerouge F, Ong E, Rositi H, Mpambani F, Berner LP, Bolbos R, Olivier C, Peyrin F, Apputukan VK, Monnereau C, Andraud C, Chaput F, Berthezène Y, Braun B, Jucker M, Åslund AK, Nyström S, Hammarström P, R Nilsson KP, Lindgren M, Wiart M, Chauveau F, Parola S. In vivo targeting and multimodal imaging of cerebral amyloid-β aggregates using hybrid GdF 3 nanoparticles. Nanomedicine (Lond) 2023; 17:2173-2187. [PMID: 36927004 DOI: 10.2217/nnm-2022-0252] [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] [Indexed: 03/18/2023] Open
Abstract
Aim: To propose a new multimodal imaging agent targeting amyloid-β (Aβ) plaques in Alzheimer's disease. Materials & methods: A new generation of hybrid contrast agents, based on gadolinium fluoride nanoparticles grafted with a pentameric luminescent-conjugated polythiophene, was designed, extensively characterized and evaluated in animal models of Alzheimer's disease through MRI, two-photon microscopy and synchrotron x-ray phase-contrast imaging. Results & conclusion: Two different grafting densities of luminescent-conjugated polythiophene were achieved while preserving colloidal stability and fluorescent properties, and without affecting biodistribution. In vivo brain uptake was dependent on the blood-brain barrier status. Nevertheless, multimodal imaging showed successful Aβ targeting in both transgenic mice and Aβ fibril-injected rats.
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Affiliation(s)
- Frédéric Lerouge
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
| | - Elodie Ong
- University of Lyon, Lyon Neuroscience Research Center, CNRS UMR, 5292, INSERM U1028, University of Lyon 1, Lyon, France
| | - Hugo Rositi
- University of Clermont Auvergne, Clermont Auvergne INP, Institut Pascal, CNRS UMR, 6602, Clermont-Ferrand, France
| | - Francis Mpambani
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
| | - Lise-Prune Berner
- University of Lyon, CREATIS, INSA-Lyon, University of Lyon 1, CNRS UMR, 5220, INSERM U1206, Villeurbanne, France
| | | | - Cécile Olivier
- University of Lyon, CREATIS, INSA-Lyon, University of Lyon 1, CNRS UMR, 5220, INSERM U1206, Villeurbanne, France
| | - Françoise Peyrin
- University of Lyon, CREATIS, INSA-Lyon, University of Lyon 1, CNRS UMR, 5220, INSERM U1206, Villeurbanne, France
| | - Vinu K Apputukan
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
| | - Cyrille Monnereau
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
| | - Chantal Andraud
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
| | - Frederic Chaput
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
| | - Yves Berthezène
- University of Lyon, CREATIS, INSA-Lyon, University of Lyon 1, CNRS UMR, 5220, INSERM U1206, Villeurbanne, France
| | - Bettina Braun
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, Germany
| | - Mathias Jucker
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, Germany
| | - Andreas Ko Åslund
- Department of Physics, Chemistry, & Biology, Linköping University, Linköping, Sweden
| | - Sofie Nyström
- Department of Physics, Chemistry, & Biology, Linköping University, Linköping, Sweden
| | - Per Hammarström
- Department of Physics, Chemistry, & Biology, Linköping University, Linköping, Sweden
| | - K Peter R Nilsson
- Department of Physics, Chemistry, & Biology, Linköping University, Linköping, Sweden
| | - Mikael Lindgren
- Department of Physics, Norwegian University of Science & Technology, Trondheim, Norway
| | - Marlène Wiart
- University of Lyon, CarMeN laboratory, INSERM U1060, INRA, U1397, University of Lyon 1, INSA-Lyon, Oullins, France.,CNRS, Villeurbanne, France
| | - Fabien Chauveau
- University of Lyon, Lyon Neuroscience Research Center, CNRS UMR, 5292, INSERM U1028, University of Lyon 1, Lyon, France
| | - Stephane Parola
- University of Lyon, École Normale Supérieure de Lyon, Laboratoire de Chimie, University of Lyon 1, CNRS UMR, 5182, Lyon, France
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Aragon MJ, Mok AT, Shea J, Wang M, Kim H, Barkdull N, Xu C, Yapici N. Multiphoton imaging of neural structure and activity in Drosophila through the intact cuticle. eLife 2022; 11:e69094. [PMID: 35073257 PMCID: PMC8846588 DOI: 10.7554/elife.69094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 01/23/2022] [Indexed: 11/13/2022] Open
Abstract
We developed a multiphoton imaging method to capture neural structure and activity in behaving flies through the intact cuticle. Our measurements showed that the fly head cuticle has surprisingly high transmission at wavelengths >900nm, and the difficulty of through-cuticle imaging is due to the air sacs and/or fat tissue underneath the head cuticle. By compressing or removing the air sacs, we performed multiphoton imaging of the fly brain through the intact cuticle. Our anatomical and functional imaging results show that 2- and 3-photon imaging are comparable in superficial regions such as the mushroom body, but 3-photon imaging is superior in deeper regions such as the central complex and beyond. We further demonstrated 2-photon through-cuticle functional imaging of odor-evoked calcium responses from the mushroom body γ-lobes in behaving flies short term and long term. The through-cuticle imaging method developed here extends the time limits of in vivo imaging in flies and opens new ways to capture neural structure and activity from the fly brain.
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Affiliation(s)
- Max Jameson Aragon
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
| | - Aaron T Mok
- School of Applied and Engineering Physics, Cornell UniversityIthacaUnited States
| | - Jamien Shea
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
| | - Mengran Wang
- School of Applied and Engineering Physics, Cornell UniversityIthacaUnited States
| | - Haein Kim
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
| | - Nathan Barkdull
- Department of Physics, University of FloridaGainesvilleUnited States
| | - Chris Xu
- School of Applied and Engineering Physics, Cornell UniversityIthacaUnited States
| | - Nilay Yapici
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
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3
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Guimarães Backhaus R, Fu T, Backhaus H, Stroh A. Pipeline for 2-photon all-optical physiology in mouse: From viral titration and optical window implantation to binarization of calcium transients. STAR Protoc 2021; 2:101010. [PMID: 35079708 PMCID: PMC8776863 DOI: 10.1016/j.xpro.2021.101010] [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] [Indexed: 11/24/2022] Open
Abstract
2-photon all-optical physiology combines in vivo 2-photon calcium imaging and optogenetics, which enables both the read out and manipulation of neuronal microcircuits with single-cell resolution. Here, we describe a protocol for achieving optimized co-expression of calcium indicator and opsin. To enable longitudinal designs, we introduce a template for virus injection and chronic window implantation. We also highlight key aspects of performing 2-photon imaging and suggest an analysis algorithm for the binarization of putatively action-potential (AP)-related calcium transients. For complete details on the use and execution of this protocol, please refer to Fu et al. (2021).
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Affiliation(s)
- Roberta Guimarães Backhaus
- Institute of Pathophysiology, University Medical Center Mainz, Hanns-Dieter-Hüsch-Weg 19, 55128 Mainz, Germany.,Leibniz Institute for Resilience Research, Wallstr. 7, 55122 Mainz, Germany
| | - Ting Fu
- Institute of Pathophysiology, University Medical Center Mainz, Hanns-Dieter-Hüsch-Weg 19, 55128 Mainz, Germany.,Leibniz Institute for Resilience Research, Wallstr. 7, 55122 Mainz, Germany
| | - Hendrik Backhaus
- Leibniz Institute for Resilience Research, Wallstr. 7, 55122 Mainz, Germany
| | - Albrecht Stroh
- Institute of Pathophysiology, University Medical Center Mainz, Hanns-Dieter-Hüsch-Weg 19, 55128 Mainz, Germany.,Leibniz Institute for Resilience Research, Wallstr. 7, 55122 Mainz, Germany
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4
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Scheiblich H, Dansokho C, Mercan D, Schmidt SV, Bousset L, Wischhof L, Eikens F, Odainic A, Spitzer J, Griep A, Schwartz S, Bano D, Latz E, Melki R, Heneka MT. Microglia jointly degrade fibrillar alpha-synuclein cargo by distribution through tunneling nanotubes. Cell 2021; 184:5089-5106.e21. [PMID: 34555357 PMCID: PMC8527836 DOI: 10.1016/j.cell.2021.09.007] [Citation(s) in RCA: 138] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 06/05/2021] [Accepted: 09/03/2021] [Indexed: 12/21/2022]
Abstract
Microglia are the CNS resident immune cells that react to misfolded proteins through pattern recognition receptor ligation and activation of inflammatory pathways. Here, we studied how microglia handle and cope with α-synuclein (α-syn) fibrils and their clearance. We found that microglia exposed to α-syn establish a cellular network through the formation of F-actin-dependent intercellular connections, which transfer α-syn from overloaded microglia to neighboring naive microglia where the α-syn cargo got rapidly and effectively degraded. Lowering the α-syn burden attenuated the inflammatory profile of microglia and improved their survival. This degradation strategy was compromised in cells carrying the LRRK2 G2019S mutation. We confirmed the intercellular transfer of α-syn assemblies in microglia using organotypic slice cultures, 2-photon microscopy, and neuropathology of patients. Together, these data identify a mechanism by which microglia create an "on-demand" functional network in order to improve pathogenic α-syn clearance.
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Affiliation(s)
- Hannah Scheiblich
- Department of Neurodegenerative Disease and Geriatric Psychiatry/Neurology, University of Bonn Medical Center, 53127 Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Cira Dansokho
- Department of Neurodegenerative Disease and Geriatric Psychiatry/Neurology, University of Bonn Medical Center, 53127 Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Dilek Mercan
- Department of Neurodegenerative Disease and Geriatric Psychiatry/Neurology, University of Bonn Medical Center, 53127 Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Susanne V Schmidt
- Institute of Innate Immunity, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Luc Bousset
- Institut François Jacob, MIRCen, CEA and Laboratory of Neurodegenerative Diseases, CNRS, 92265 Fontenay-aux-Roses, France
| | - Lena Wischhof
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Frederik Eikens
- Department of Neurodegenerative Disease and Geriatric Psychiatry/Neurology, University of Bonn Medical Center, 53127 Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Alexandru Odainic
- Institute of Innate Immunity, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Jasper Spitzer
- Institute of Innate Immunity, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Angelika Griep
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Stephanie Schwartz
- Department of Neurodegenerative Disease and Geriatric Psychiatry/Neurology, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Eicke Latz
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; Institute of Innate Immunity, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Ronald Melki
- Institut François Jacob, MIRCen, CEA and Laboratory of Neurodegenerative Diseases, CNRS, 92265 Fontenay-aux-Roses, France
| | - Michael T Heneka
- Department of Neurodegenerative Disease and Geriatric Psychiatry/Neurology, University of Bonn Medical Center, 53127 Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; Divison of Infectious Diseases and Immunology, University of Massachusetts Medical School, 01605 Worcester, MA, USA.
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5
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Luo Z, Xu H, Liu L, Ohulchanskyy TY, Qu J. Optical Imaging of Beta-Amyloid Plaques in Alzheimer's Disease. BIOSENSORS 2021; 11:255. [PMID: 34436057 PMCID: PMC8392287 DOI: 10.3390/bios11080255] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/21/2021] [Accepted: 07/26/2021] [Indexed: 02/02/2023]
Abstract
Alzheimer's disease (AD) is a multifactorial, irreversible, and incurable neurodegenerative disease. The main pathological feature of AD is the deposition of misfolded β-amyloid protein (Aβ) plaques in the brain. The abnormal accumulation of Aβ plaques leads to the loss of some neuron functions, further causing the neuron entanglement and the corresponding functional damage, which has a great impact on memory and cognitive functions. Hence, studying the accumulation mechanism of Aβ in the brain and its effect on other tissues is of great significance for the early diagnosis of AD. The current clinical studies of Aβ accumulation mainly rely on medical imaging techniques, which have some deficiencies in sensitivity and specificity. Optical imaging has recently become a research hotspot in the medical field and clinical applications, manifesting noninvasiveness, high sensitivity, absence of ionizing radiation, high contrast, and spatial resolution. Moreover, it is now emerging as a promising tool for the diagnosis and study of Aβ buildup. This review focuses on the application of the optical imaging technique for the determination of Aβ plaques in AD research. In addition, recent advances and key operational applications are discussed.
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Affiliation(s)
| | | | | | | | - Junle Qu
- Center for Biomedical Photonics, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; (Z.L.); (H.X.); (L.L.); (T.Y.O.)
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6
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Groblewski PA, Sullivan D, Lecoq J, de Vries SEJ, Caldejon S, L'Heureux Q, Keenan T, Roll K, Slaughterback C, Williford A, Farrell C. A standardized head-fixation system for performing large-scale, in vivo physiological recordings in mice. J Neurosci Methods 2020; 346:108922. [PMID: 32946912 DOI: 10.1016/j.jneumeth.2020.108922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND The Allen Institute recently built a set of high-throughput experimental pipelines to collect comprehensive in vivo surveys of physiological activity in the visual cortex of awake, head-fixed mice. Developing these large-scale, industrial-like pipelines posed many scientific, operational, and engineering challenges. NEW METHOD Our strategies for creating a cross-platform reference space to which all pipeline datasets were mapped required development of 1) a robust headframe, 2) a reproducible clamping system, and 3) data-collection systems that are built, and maintained, around precise alignment with a reference artifact. RESULTS When paired with our pipeline clamping system, our headframe exceeded deflection and reproducibility requirements. By leveraging our headframe and clamping system we were able to create a cross-platform reference space to which multi-modal imaging datasets could be mapped. COMPARISON WITH EXISTING METHODS Together, the Allen Brain Observatory headframe, surgical tooling, clamping system, and system registration strategy create a unique system for collecting large amounts of standardized in vivo datasets over long periods of time. Moreover, the integrated approach to cross-platform registration allows for multi-modal datasets to be collected within a shared reference space. CONCLUSIONS Here we report the engineering strategies that we implemented when creating the Allen Brain Observatory physiology pipelines. All of the documentation related to headframe, surgical tooling, and clamp design has been made freely available and can be readily manufactured or procured. The engineering strategy, or components of the strategy, described in this report can be tailored and applied by external researchers to improve data standardization and stability.
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Affiliation(s)
- P A Groblewski
- Allen Institute for Brain Science, Seattle, WA, 98109, USA.
| | - D Sullivan
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - J Lecoq
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - S E J de Vries
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - S Caldejon
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - Q L'Heureux
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - T Keenan
- Amazon Logistics, Bellevue, WA, 98004, USA
| | - K Roll
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | | | - A Williford
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - C Farrell
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
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7
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Medin aggregation causes cerebrovascular dysfunction in aging wild-type mice. Proc Natl Acad Sci U S A 2020; 117:23925-23931. [PMID: 32900929 DOI: 10.1073/pnas.2011133117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Medin is the most common amyloid known in humans, as it can be found in blood vessels of the upper body in virtually everybody over 50 years of age. However, it remains unknown whether deposition of Medin plays a causal role in age-related vascular dysfunction. We now report that aggregates of Medin also develop in the aorta and brain vasculature of wild-type mice in an age-dependent manner. Strikingly, genetic deficiency of the Medin precursor protein, MFG-E8, eliminates not only vascular aggregates but also prevents age-associated decline of cerebrovascular function in mice. Given the prevalence of Medin aggregates in the general population and its role in vascular dysfunction with aging, targeting Medin may become a novel approach to sustain healthy aging.
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Bernier LP, Bohlen CJ, York EM, Choi HB, Kamyabi A, Dissing-Olesen L, Hefendehl JK, Collins HY, Stevens B, Barres BA, MacVicar BA. Nanoscale Surveillance of the Brain by Microglia via cAMP-Regulated Filopodia. Cell Rep 2020; 27:2895-2908.e4. [PMID: 31167136 DOI: 10.1016/j.celrep.2019.05.010] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/14/2019] [Accepted: 04/30/2019] [Indexed: 02/07/2023] Open
Abstract
Microglia, the brain's immune cells, maintain homeostasis and sense pathological changes by continuously surveying the parenchyma with highly motile large processes. Here, we demonstrate that microglia also use thin actin-dependent filopodia that allow fast nanoscale sensing within discrete regions. Filopodia are distinct from large processes by their size, speed, and regulation mechanism. Increasing cyclic AMP (cAMP) by activating norepinephrine Gs-coupled receptors, applying nitric oxide, or inhibiting phosphodiesterases rapidly increases filopodia but collapses large processes. Alternatively, Gi-coupled P2Y12 receptor activation collapses filopodia but triggers large processes extension with bulbous tips. Similar control of cytoskeletal dynamics and microglial morphology by cAMP is observed in ramified primary microglia, suggesting that filopodia are intrinsically generated sensing structures. Therefore, nanoscale surveillance of brain parenchyma by microglia requires localized cAMP increases that drive filopodia formation. Shifting intracellular cAMP levels controls the polarity of microglial responses to changes in brain homeostasis and alters the scale of immunosurveillance.
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Affiliation(s)
- Louis-Philippe Bernier
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada.
| | - Christopher J Bohlen
- Stanford University School of Medicine, Department of Neurobiology, Stanford, CA 94305, USA
| | - Elisa M York
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Hyun B Choi
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Alireza Kamyabi
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Lasse Dissing-Olesen
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School Boston, MA 02115, USA
| | - Jasmin K Hefendehl
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Hannah Y Collins
- Stanford University School of Medicine, Department of Neurobiology, Stanford, CA 94305, USA
| | - Beth Stevens
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School Boston, MA 02115, USA
| | - Ben A Barres
- Stanford University School of Medicine, Department of Neurobiology, Stanford, CA 94305, USA
| | - Brian A MacVicar
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada.
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9
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Drost N, Houtman J, Cseresnyés Z, Niesner R, Rinnenthal JL, Miller KR, Prokop S, Heppner FL. The Amyloid-beta rich CNS environment alters myeloid cell functionality independent of their origin. Sci Rep 2020; 10:7152. [PMID: 32346002 PMCID: PMC7189379 DOI: 10.1038/s41598-020-63989-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 04/02/2020] [Indexed: 01/08/2023] Open
Abstract
Microglia, the innate immune cells of the central nervous system (CNS) survey their surroundings with their cytoplasmic processes, phagocytose debris and rapidly respond to injury. These functions are affected by the presence of beta-Amyloid (Aβ) deposits, hallmark lesions of Alzheimer's disease (AD). We recently demonstrated that exchanging functionally altered endogenous microglia with peripheral myeloid cells did not change Aβ-burden in a mouse model mimicking aspects of AD at baseline, and only mildly reduced Aβ plaques upon stimulation. To better characterize these different myeloid cell populations, we used long-term in vivo 2-photon microscopy to compare morphology and basic functional parameters of brain populating peripherally-derived myeloid cells and endogenous microglia. While peripherally-derived myeloid cells exhibited increased process movement in the non-diseased brain, the Aβ rich environment in an AD-like mouse model, which induced an alteration of surveillance functions in endogenous microglia, also restricted functional characteristics and response to CNS injury of newly recruited peripherally-derived myeloid cells. Our data demonstrate that the Aβ rich brain environment alters the functional characteristics of endogenous microglia as well as newly recruited peripheral myeloid cells, which has implications for the role of myeloid cells in disease and the utilization of these cells in Alzheimer's disease therapy.
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Affiliation(s)
- Natalia Drost
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
| | - Judith Houtman
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE) Dresden, 01307, Dresden, Germany
| | - Zoltán Cseresnyés
- Deutsches Rheuma-Forschungszentrum Berlin, a Leibniz Institute, Charitéplatz 1, 10117, Berlin, Germany
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Raluca Niesner
- Deutsches Rheuma-Forschungszentrum Berlin, a Leibniz Institute, Charitéplatz 1, 10117, Berlin, Germany
- Veterinary Medicine, Freie Universität, Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Jan-Leo Rinnenthal
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
- Department of Pathology, Sana Klinikum Offenbach, 63069, Offenbach, Germany
| | - Kelly R Miller
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
- Nanostring Technologies, Seattle, WA, USA
| | - Stefan Prokop
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
- Department of Pathology, University of Florida, Gainesville, FL, United States
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
- Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Frank L Heppner
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany.
- Cluster of Excellence, NeuroCure, Charitéplatz 1, 10117, Berlin, Germany.
- Berlin Institute of Health (BIH), 10117, Berlin, Germany.
- German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117, Berlin, Germany.
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10
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Structure–function relationships in peripheral nerve contributions to diabetic peripheral neuropathy. Pain 2019; 160 Suppl 1:S29-S36. [DOI: 10.1097/j.pain.0000000000001530] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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11
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Zhang J, Konsmo A, Sandberg A, Wu X, Nyström S, Obermüller U, Wegenast-Braun BM, Konradsson P, Lindgren M, Hammarström P. Phenolic Bis-styrylbenzo[c]-1,2,5-thiadiazoles as Probes for Fluorescence Microscopy Mapping of Aβ Plaque Heterogeneity. J Med Chem 2019; 62:2038-2048. [DOI: 10.1021/acs.jmedchem.8b01681] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jun Zhang
- Division of Chemistry, Department of Physics Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Audun Konsmo
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Alexander Sandberg
- Division of Chemistry, Department of Physics Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Xiongyu Wu
- Division of Chemistry, Department of Physics Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Sofie Nyström
- Division of Chemistry, Department of Physics Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Ulrike Obermüller
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- DZNE−German Center for Neurodegenerative Diseases, 72076 Tübingen, Germany
| | - Bettina M. Wegenast-Braun
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- DZNE−German Center for Neurodegenerative Diseases, 72076 Tübingen, Germany
| | - Peter Konradsson
- Division of Chemistry, Department of Physics Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Mikael Lindgren
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Per Hammarström
- Division of Chemistry, Department of Physics Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
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12
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Innate immune memory in the brain shapes neurological disease hallmarks. Nature 2018; 556:332-338. [PMID: 29643512 PMCID: PMC6038912 DOI: 10.1038/s41586-018-0023-4] [Citation(s) in RCA: 547] [Impact Index Per Article: 91.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 02/23/2018] [Indexed: 12/20/2022]
Abstract
‘Innate immune memory’ is a vital mechanism of myeloid cell
plasticity that occurs in response to environmental stimuli and alters
subsequent immune responses. Two types of immunological imprinting can be
distinguished, training and tolerance, which
are epigenetically mediated and enhance or suppress subsequent inflammation,
respectively. Whether immune memory occurs in tissue-resident macrophages
in vivo and how it may affect pathology remains largely
unknown. Here we demonstrate that peripherally applied inflammatory stimuli
induce acute immune training and tolerance in the brain and lead to differential
epigenetic reprogramming of brain-resident macrophages, microglia, that persists
for at least six months. Strikingly, in a mouse model of Alzheimer’s
pathology, immune training exacerbates cerebral β-amyloidosis while
tolerance alleviates it; similarly, peripheral immune stimulation modifies
pathological features after stroke. Our results identify immune memory in the
brain as an important modifier of neuropathology.
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13
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Kaczmarczyk R, Tejera D, Simon BJ, Heneka MT. Microglia modulation through external vagus nerve stimulation in a murine model of Alzheimer's disease. J Neurochem 2017; 146:76-85. [PMID: 29266221 DOI: 10.1111/jnc.14284] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 11/24/2017] [Accepted: 12/04/2017] [Indexed: 01/04/2023]
Abstract
Chronically activated microglia contribute to the development of neurodegenerative diseases such as Alzheimer's disease (AD) by the release of pro-inflammatory mediators that compromise neuronal function and structure. Modulating microglia functions could be instrumental to interfere with disease pathogenesis. Previous studies have shown anti-inflammatory effects of acetylcholine (ACh) or norepinephrine (NE), which mainly activates the β-receptors on microglial cells. Non-invasive vagus nerve stimulation (nVNS) is used in treatment of drug-resistant depression, which is a risk factor for developing AD. The vagus nerve projects to the brainstem's locus coeruleus from which noradrenergic fibers reach to the Nucleus Basalis of Meynert (NBM) and widely throughout the brain. Pilot studies showed first signs of cognitive-enhancing effects of nVNS in AD patients. In this study, the effects of nVNS on mouse microglia cell morphology were analyzed over a period of 280 min by 2-photon laser scanning in vivo microscopy. Total branch length, average branch order and number of branches, which are commonly used indicators for the microglial activation state were determined and compared between young and old wild-type and amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice. Overall, these experiments show strong morphological changes in microglia, from a neurodestructive to a neuroprotective phenotype, following a brief nVNS in aged animals, especially in APP/PS1 animals, whereas microglia from young animals were morphologically unaffected.
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Affiliation(s)
- Robert Kaczmarczyk
- Department of Neurodegenerative Disease and Gerontopsychiatry, University of Bonn, Bonn, Germany
| | - Dario Tejera
- Department of Neurodegenerative Disease and Gerontopsychiatry, University of Bonn, Bonn, Germany
| | | | - Michael T Heneka
- Department of Neurodegenerative Disease and Gerontopsychiatry, University of Bonn, Bonn, Germany
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14
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Füger P, Hefendehl JK, Veeraraghavalu K, Wendeln AC, Schlosser C, Obermüller U, Wegenast-Braun BM, Neher JJ, Martus P, Kohsaka S, Thunemann M, Feil R, Sisodia SS, Skodras A, Jucker M. Microglia turnover with aging and in an Alzheimer's model via long-term in vivo single-cell imaging. Nat Neurosci 2017; 20:1371-1376. [PMID: 28846081 DOI: 10.1038/nn.4631] [Citation(s) in RCA: 248] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 08/02/2017] [Indexed: 12/29/2022]
Abstract
To clarify the role of microglia in brain homeostasis and disease, an understanding of their maintenance, proliferation and turnover is essential. The lifespan of brain microglia, however, remains uncertain, and reflects confounding factors in earlier assessments that were largely indirect. We genetically labeled single resident microglia in living mice and then used multiphoton microscopy to monitor these cells over time. Under homeostatic conditions, we found that neocortical resident microglia were long-lived, with a median lifetime of well over 15 months; thus, approximately half of these cells survive the entire mouse lifespan. While proliferation of resident neocortical microglia under homeostatic conditions was low, microglial proliferation in a mouse model of Alzheimer's β-amyloidosis was increased threefold. The persistence of individual microglia throughout the mouse lifespan provides an explanation for how microglial priming early in life can induce lasting functional changes and how microglial senescence may contribute to age-related neurodegenerative diseases.
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Affiliation(s)
- Petra Füger
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Jasmin K Hefendehl
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
| | | | - Ann-Christin Wendeln
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany.,Graduate School of Cellular and Molecular Neuroscience, University of Tübingen, Tübingen, Germany
| | - Christine Schlosser
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Ulrike Obermüller
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Bettina M Wegenast-Braun
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Jonas J Neher
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Peter Martus
- Institute of Medical Biometry, University of Tübingen, Tübingen, Germany
| | - Shinichi Kohsaka
- Department of Neurochemistry, National Institute of Neuroscience, Kodaira, Tokyo, Japan
| | - Martin Thunemann
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Robert Feil
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Sangram S Sisodia
- Department of Neurobiology, The University of Chicago, Chicago, Illinois, USA
| | - Angelos Skodras
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Mathias Jucker
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,DZNE-German Center for Neurodegenerative Diseases, Tübingen, Germany
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15
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Marchand PJ, Bouwens A, Bolmont T, Shamaei VK, Nguyen D, Szlag D, Extermann J, Lasser T. Statistical parametric mapping of stimuli evoked changes in total blood flow velocity in the mouse cortex obtained with extended-focus optical coherence microscopy. BIOMEDICAL OPTICS EXPRESS 2017; 8:1-15. [PMID: 28101397 PMCID: PMC5231283 DOI: 10.1364/boe.8.000001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/11/2016] [Accepted: 11/26/2016] [Indexed: 05/08/2023]
Abstract
Functional magnetic resonance (fMRI) imaging is the current gold-standard in neuroimaging. fMRI exploits local changes in blood oxygenation to map neuronal activity over the entire brain. However, its spatial resolution is currently limited to a few hundreds of microns. Here we use extended-focus optical coherence microscopy (xfOCM) to quantitatively measure changes in blood flow velocity during functional hyperaemia at high spatio-temporal resolution in the somatosensory cortex of mice. As optical coherence microscopy acquires hundreds of depth slices simultaneously, blood flow velocity measurements can be performed over several vessels in parallel. We present the proof-of-principle of an optimised statistical parametric mapping framework to analyse quantitative blood flow timetraces acquired with xfOCM using the general linear model. We demonstrate the feasibility of generating maps of cortical hemodynamic reactivity at the capillary level with optical coherence microscopy. To validate our method, we exploited 3 stimulation paradigms, covering different temporal dynamics and stimulated limbs, and demonstrated its repeatability over 2 trials, separated by a week.
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16
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Hefendehl JK, LeDue J, Ko RWY, Mahler J, Murphy TH, MacVicar BA. Mapping synaptic glutamate transporter dysfunction in vivo to regions surrounding Aβ plaques by iGluSnFR two-photon imaging. Nat Commun 2016; 7:13441. [PMID: 27834383 PMCID: PMC5114608 DOI: 10.1038/ncomms13441] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/04/2016] [Indexed: 12/22/2022] Open
Abstract
Amyloid-β (Aβ) plaques, a hallmark of Alzheimer's disease (AD), are surrounded by regions of neuronal and glial hyperactivity. We use in vivo two-photon and wide-field imaging of the glutamate sensor iGluSnFR to determine whether pathological changes in glutamate dynamics in the immediate vicinity of Aβ deposits in APPPS1 transgenic mice could alter neuronal activity in this microenvironment. In regions close to Aβ plaques chronic states of high spontaneous glutamate fluctuations are observed and the timing of glutamate responses evoked by sensory stimulation exhibit slower decay rates in two cortical brain areas. GLT-1 expression is reduced around Aβ plaques and upregulation of GLT-1 expression and activity by ceftriaxone partially restores glutamate dynamics to values in control regions. We conclude that the toxic microenvironment surrounding Aβ plaques results, at least partially, from enhanced glutamate levels and that pharmacologically increasing GLT-1 expression and activity may be a new target for early therapeutic intervention. In Alzheimer's disease (AD), neural hyperactivity has been shown to occur in the regions surrounding Aβ plaques. Here, the authors use in vivo two-photon imaging in mouse models of AD and report abnormal glutamate dynamics in the vicinity of plaques which can be partially restored via GLT-1 upregulation through Ceftriaxone treatment.
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Affiliation(s)
- J K Hefendehl
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - J LeDue
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - R W Y Ko
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - J Mahler
- Hertie-Institut für klinische Hirnforschung, Otfried-Müller-Strasse 27, 72076 Tübingen, Germany
| | - T H Murphy
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - B A MacVicar
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
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17
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Silasi G, Xiao D, Vanni MP, Chen ACN, Murphy TH. Intact skull chronic windows for mesoscopic wide-field imaging in awake mice. J Neurosci Methods 2016; 267:141-9. [PMID: 27102043 DOI: 10.1016/j.jneumeth.2016.04.012] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 04/09/2016] [Accepted: 04/16/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Craniotomy-based window implants are commonly used for microscopic imaging, in head-fixed rodents, however their field of view is typically small and incompatible with mesoscopic functional mapping of cortex. NEW METHOD We describe a reproducible and simple procedure for chronic through-bone wide-field imaging in awake head-fixed mice providing stable optical access for chronic imaging over large areas of the cortex for months. RESULTS The preparation is produced by applying clear-drying dental cement to the intact mouse skull, followed by a glass coverslip to create a partially transparent imaging surface. Surgery time takes about 30min. A single set-screw provides a stable means of attachment (in relation to the measured lateral and axial resolution) for mesoscale assessment without obscuring the cortical field of view. COMPARISON WITH EXISTING METHODS We demonstrate the utility of this method by showing seed-pixel functional connectivity maps generated from spontaneous cortical activity of GCAMP6 signals in both awake and anesthetized mice in longitudinal studies of up to 2 months in duration. CONCLUSIONS We propose that the intact skull preparation described here may be used for most longitudinal studies that do not require micron scale resolution and where cortical neural or vascular signals are recorded with intrinsic sensors or in transgenic mice expressing genetically encoded sensors of activity.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Dongsheng Xiao
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Matthieu P Vanni
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Andrew C N Chen
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
| | - Timothy H Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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18
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Abstract
Classical conditioning that involves mnemonic processing, that is, a "trace" period between conditioned and unconditioned stimulus, requires awareness of the association to be formed and is considered a simple model paradigm for declarative learning. Barrel cortex, the whisker representation of primary somatosensory cortex, is required for the learning of a tactile variant of trace eyeblink conditioning (TTEBC) and undergoes distinct map plasticity during learning. To investigate the cellular mechanism underpinning TTEBC and concurrent map plasticity, we used two-photon imaging of dendritic spines in barrel cortex of awake mice while being conditioned. Monitoring layer 5 neurons' apical dendrites in layer 1, we show that one cellular expression of barrel cortex plasticity is a substantial spine count reduction of ∼15% of the dendritic spines present before learning. The number of eliminated spines and their time of elimination are tightly related to the learning success. Moreover, spine plasticity is highly specific for the principal barrel column receiving the main signals from the stimulated vibrissa. Spines located in other columns, even those directly adjacent to the principal column, are unaffected. Because layer 1 spines integrate signals from associative thalamocortical circuits, their column-specific elimination suggests that this spine plasticity may be the result of an association of top-down signals relevant for declarative learning and spatially precise ascending tactile signals.
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19
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Activation of neuronal NMDA receptors triggers transient ATP-mediated microglial process outgrowth. J Neurosci 2014; 34:10511-27. [PMID: 25100586 DOI: 10.1523/jneurosci.0405-14.2014] [Citation(s) in RCA: 193] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Microglia are morphologically dynamic cells that rapidly extend their processes in response to various stimuli including extracellular ATP. In this study, we tested the hypothesis that stimulation of neuronal NMDARs trigger ATP release leading to communication with microglia. We used acute mouse hippocampal brain slices and two-photon laser scanning microscopy to study microglial dynamics and developed a novel protocol for fixation and immunolabeling of microglia processes. Similar to direct topical ATP application in vivo, short multiple applications of NMDA triggered transient microglia process outgrowth that was reversible and repeatable indicating that this was not due to excitotoxic damage. Stimulation of NMDAR was required as NMDAR antagonists, but not blockers of AMPA/kainate receptors or voltage-gated sodium channels, prevented microglial outgrowth. We report that ATP release, secondary to NMDAR activation, was the key mediator of this neuron-microglia communication as both blocking purinergic receptors and inhibiting hydrolysis of ATP to prevent locally generated gradients abolished outgrowth. Pharmacological and genetic analyses showed that the NMDA-triggered microglia process extension was independent of Pannexin 1, the ATP releasing channels, ATP release from astrocytes via connexins, and nitric oxide generation. Finally, using whole-cell patch clamping we demonstrate that activation of dendritic NMDAR on single neurons is sufficient to trigger microglia process outgrowth. Our results suggest that dendritic neuronal NMDAR activation triggers ATP release via a Pannexin 1-independent manner that induces outgrowth of microglia processes. This represents a novel uncharacterized form of neuron-microglial communication mediated by ATP.
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20
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Fumagalli S, Ortolano F, De Simoni MG. A close look at brain dynamics: Cells and vessels seen by in vivo two-photon microscopy. Prog Neurobiol 2014; 121:36-54. [DOI: 10.1016/j.pneurobio.2014.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 06/17/2014] [Accepted: 06/29/2014] [Indexed: 01/11/2023]
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21
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Hefendehl JK, Neher JJ, Sühs RB, Kohsaka S, Skodras A, Jucker M. Homeostatic and injury-induced microglia behavior in the aging brain. Aging Cell 2014; 13:60-9. [PMID: 23953759 PMCID: PMC4326865 DOI: 10.1111/acel.12149] [Citation(s) in RCA: 210] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2013] [Indexed: 12/20/2022] Open
Abstract
Microglia cells are essential for brain homeostasis and have essential roles in neurodegenerative diseases. Aging is the main risk factor for most neurodegenerative diseases, and age-related changes in microglia may contribute to the susceptibility of the aging brain to dysfunction and neurodegeneration. We have analyzed morphology and dynamic behavior of neocortical microglia in their physiological environment in young adult (3-month-old), adult (11- to 12-month-old), and aged (26- to 27-month-old) C57BL/6J-Iba1-eGFP mice using in vivo 2-photon microscopy. Results show that surveying microglial cells in the neocortex exhibit age-related soma volume increase, shortening of processes, and loss of homogeneous tissue distribution. Furthermore, microglial process speed significantly decreased with age. While only a small population of microglia showed soma movement in adult mice, the microglia population with soma movement was increased in aged mice. However, in response to tissue injury, the dynamic microglial response was age-dependently diminished. These results provide novel insights into microglial behavior and indicate that microglial dysfunction in the aging brain may contribute to age-related cognitive decline and neurodegenerative diseases.
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Affiliation(s)
- Jasmin K Hefendehl
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of TübingenD-72076, Tübingen, Germany
| | - Jonas J Neher
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of TübingenD-72076, Tübingen, Germany
| | - Rafael B Sühs
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of TübingenD-72076, Tübingen, Germany
| | - Shinichi Kohsaka
- Department of Neurochemistry, National Institute of NeuroscienceKodaira, Tokyo, 187-8502, Japan
| | - Angelos Skodras
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of TübingenD-72076, Tübingen, Germany
- DZNE, German Center for Neurodegenerative DiseasesD-72076, Tübingen, Germany
| | - Mathias Jucker
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of TübingenD-72076, Tübingen, Germany
- DZNE, German Center for Neurodegenerative DiseasesD-72076, Tübingen, Germany
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22
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Bouwens A, Bolmont T, Szlag D, Berclaz C, Lasser T. Quantitative cerebral blood flow imaging with extended-focus optical coherence microscopy. OPTICS LETTERS 2014; 39:37-40. [PMID: 24365816 DOI: 10.1364/ol.39.000037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Quantitative three-dimensional blood flow imaging is a valuable technique to investigate the physiology of the brain. Two-photon microscopy (2PM) allows quantification of the local blood flow velocity with micrometric resolution by performing repeated line scans, but prohibitively long measurement times would be required to apply this technique to full three-dimensional volumes. By multiplexing the image acquisition over depth, Fourier domain optical coherence tomography (FDOCT) enables quantification of blood flow velocities with a high volume acquisition rate, albeit at a relatively low spatial resolution. Extended-focus optical coherence microscopy (xfOCM) increases the lateral resolution without sacrificing depth of field and therefore combines the high volume acquisition rate of FDOCT with a resolution comparable to 2PM. Here, we demonstrate high-resolution quantitative imaging of the blood flow velocity vector's magnitude in the adult murine brain with xfOCM.
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