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Altas B, Tuffy LP, Patrizi A, Dimova K, Soykan T, Brandenburg C, Romanowski AJ, Whitten JR, Robertson CD, Khim SN, Crutcher GW, Ambrozkiewicz MC, Yagensky O, Krueger-Burg D, Hammer M, Hsiao HH, Laskowski PR, Dyck L, Puche AC, Sassoè-Pognetto M, Chua JJE, Urlaub H, Jahn O, Brose N, Poulopoulos A. Region-Specific Phosphorylation Determines Neuroligin-3 Localization to Excitatory Versus Inhibitory Synapses. Biol Psychiatry 2023:S0006-3223(23)01799-7. [PMID: 38154503 PMCID: PMC11209832 DOI: 10.1016/j.biopsych.2023.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
BACKGROUND Neuroligin-3 is a postsynaptic adhesion molecule involved in synapse development and function. It is implicated in rare, monogenic forms of autism, and its shedding is critical to the tumor microenvironment of gliomas. While other members of the neuroligin family exhibit synapse-type specificity in localization and function through distinct interactions with postsynaptic scaffold proteins, the specificity of neuroligin-3 synaptic localization remains largely unknown. METHODS We investigated the synaptic localization of neuroligin-3 across regions in mouse and human brain samples after validating antibody specificity in knockout animals. We raised a phospho-specific neuroligin antibody and used phosphoproteomics, cell-based assays, and in utero CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/Cas9) knockout and gene replacement to identify mechanisms that regulate neuroligin-3 localization to distinct synapse types. RESULTS Neuroligin-3 exhibits region-dependent synapse specificity, largely localizing to excitatory synapses in cortical regions and inhibitory synapses in subcortical regions of the brain in both mice and humans. We identified specific phosphorylation of cortical neuroligin-3 at a key binding site for recruitment to inhibitory synapses, while subcortical neuroligin-3 remained unphosphorylated. In vitro, phosphomimetic mutation of that site disrupted neuroligin-3 association with the inhibitory postsynaptic scaffolding protein gephyrin. In vivo, phosphomimetic mutants of neuroligin-3 localized to excitatory postsynapses, while phospho-null mutants localized to inhibitory postsynapses. CONCLUSIONS These data reveal an unexpected region-specific pattern of neuroligin-3 synapse specificity, as well as a phosphorylation-dependent mechanism that regulates its recruitment to either excitatory or inhibitory synapses. These findings add to our understanding of how neuroligin-3 is involved in conditions that may affect the balance of excitation and inhibition.
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Affiliation(s)
- Bekir Altas
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Liam P Tuffy
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Annarita Patrizi
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Kalina Dimova
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Tolga Soykan
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Cheryl Brandenburg
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea J Romanowski
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Julia R Whitten
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Colin D Robertson
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Saovleak N Khim
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Garrett W Crutcher
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mateusz C Ambrozkiewicz
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Oleksandr Yagensky
- Research Group Protein Trafficking in Synaptic Development and Function, Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Matthieu Hammer
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - He-Hsuan Hsiao
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Pawel R Laskowski
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lydia Dyck
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Adam C Puche
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
| | | | - John J E Chua
- Research Group Protein Trafficking in Synaptic Development and Function, Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Olaf Jahn
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Alexandros Poulopoulos
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland; Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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Kuljis DA, Micheva KD, Ray A, Wegner W, Bowman R, Madison DV, Willig KI, Barth AL. Gephyrin-Lacking PV Synapses on Neocortical Pyramidal Neurons. Int J Mol Sci 2021; 22:ijms221810032. [PMID: 34576197 PMCID: PMC8467468 DOI: 10.3390/ijms221810032] [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: 07/30/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 11/26/2022] Open
Abstract
Gephyrin has long been thought of as a master regulator for inhibitory synapses, acting as a scaffold to organize γ-aminobutyric acid type A receptors (GABAARs) at the post-synaptic density. Accordingly, gephyrin immunostaining has been used as an indicator of inhibitory synapses; despite this, the pan-synaptic localization of gephyrin to specific classes of inhibitory synapses has not been demonstrated. Genetically encoded fibronectin intrabodies generated with mRNA display (FingRs) against gephyrin (Gephyrin.FingR) reliably label endogenous gephyrin, and can be tagged with fluorophores for comprehensive synaptic quantitation and monitoring. Here we investigated input- and target-specific localization of gephyrin at a defined class of inhibitory synapse, using Gephyrin.FingR proteins tagged with EGFP in brain tissue from transgenic mice. Parvalbumin-expressing (PV) neuron presynaptic boutons labeled using Cre- dependent synaptophysin-tdTomato were aligned with postsynaptic Gephyrin.FingR puncta. We discovered that more than one-third of PV boutons adjacent to neocortical pyramidal (Pyr) cell somas lack postsynaptic gephyrin labeling. This finding was confirmed using correlative fluorescence and electron microscopy. Our findings suggest some inhibitory synapses may lack gephyrin. Gephyrin-lacking synapses may play an important role in dynamically regulating cell activity under different physiological conditions.
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Affiliation(s)
- Dika A. Kuljis
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
| | - Kristina D. Micheva
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, CA 94304, USA; (K.D.M.); (D.V.M.)
| | - Ajit Ray
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
| | - Waja Wegner
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37075 Göttingen, Germany; (W.W.); (K.I.W.)
- Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Ryan Bowman
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
| | - Daniel V. Madison
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, CA 94304, USA; (K.D.M.); (D.V.M.)
| | - Katrin I. Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37075 Göttingen, Germany; (W.W.); (K.I.W.)
- Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Alison L. Barth
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
- Correspondence: ; Tel.: +1-412-268-1198
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Briatore F, Pregno G, Di Angelantonio S, Frola E, De Stefano ME, Vaillend C, Sassoè-Pognetto M, Patrizi A. Dystroglycan Mediates Clustering of Essential GABAergic Components in Cerebellar Purkinje Cells. Front Mol Neurosci 2020; 13:164. [PMID: 32982691 PMCID: PMC7485281 DOI: 10.3389/fnmol.2020.00164] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/11/2020] [Indexed: 01/02/2023] Open
Abstract
Muscle dystrophin–glycoprotein complex (DGC) links the intracellular cytoskeleton to the extracellular matrix. In neurons, dystroglycan and dystrophin, two major components of the DGC, localize in a subset of GABAergic synapses, where their function is unclear. Here we used mouse models to analyze the specific role of the DGC in the organization and function of inhibitory synapses. Loss of full-length dystrophin in mdx mice resulted in a selective depletion of the transmembrane β-dystroglycan isoform from inhibitory post-synaptic sites in cerebellar Purkinje cells. Remarkably, there were no differences in the synaptic distribution of the extracellular α-dystroglycan subunit, of GABAA receptors and neuroligin 2. In contrast, conditional deletion of the dystroglycan gene from Purkinje cells caused a disruption of the DGC and severely impaired post-synaptic clustering of neuroligin 2, GABAA receptors and scaffolding proteins. Accordingly, whole-cell patch-clamp analysis revealed a significant reduction in the frequency and amplitude of spontaneous IPSCs recorded from Purkinje cells. In the long-term, deletion of dystroglycan resulted in a significant decrease of GABAergic innervation of Purkinje cells and caused an impairment of motor learning functions. These results show that dystroglycan is an essential synaptic organizer at GABAergic synapses in Purkinje cells.
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Affiliation(s)
- Federica Briatore
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Giulia Pregno
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,Center for Life Nanoscience, Istituto Italiano di Tecnologia, Rome, Italy
| | - Elena Frola
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Maria Egle De Stefano
- Department of Biology and Biotechnology "Charles Darwin", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Cyrille Vaillend
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Marco Sassoè-Pognetto
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Annarita Patrizi
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy.,Schaller Research Group Leader at the German Cancer Research Center, Heidelberg, Germany
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Chiu CQ, Martenson JS, Yamazaki M, Natsume R, Sakimura K, Tomita S, Tavalin SJ, Higley MJ. Input-Specific NMDAR-Dependent Potentiation of Dendritic GABAergic Inhibition. Neuron 2019; 97:368-377.e3. [PMID: 29346754 DOI: 10.1016/j.neuron.2017.12.032] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 11/16/2017] [Accepted: 12/21/2017] [Indexed: 01/21/2023]
Abstract
Preservation of a balance between synaptic excitation and inhibition is critical for normal brain function. A number of homeostatic cellular mechanisms have been suggested to play a role in maintaining this balance, including long-term plasticity of GABAergic inhibitory synapses. Many previous studies have demonstrated a coupling of postsynaptic spiking with modification of perisomatic inhibition. Here, we demonstrate that activation of NMDA-type glutamate receptors leads to input-specific long-term potentiation of dendritic inhibition mediated by somatostatin-expressing interneurons. This form of plasticity is expressed postsynaptically and requires both CaMKIIα and the β2 subunit of the GABA-A receptor. Importantly, this process may function to preserve dendritic inhibition, as genetic deletion of NMDAR signaling results in a selective weakening of dendritic inhibition. Overall, our results reveal a new mechanism for linking excitatory and inhibitory input in neuronal dendrites and provide novel insight into the homeostatic regulation of synaptic transmission in cortical circuits.
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Affiliation(s)
- Chiayu Q Chiu
- Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration, and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - James S Martenson
- Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration, and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Rie Natsume
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Susumu Tomita
- Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration, and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Steven J Tavalin
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38103, USA
| | - Michael J Higley
- Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration, and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA.
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5
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Chattaragada MS, Riganti C, Sassoe M, Principe M, Santamorena MM, Roux C, Curcio C, Evangelista A, Allavena P, Salvia R, Rusev B, Scarpa A, Cappello P, Novelli F. FAM49B, a novel regulator of mitochondrial function and integrity that suppresses tumor metastasis. Oncogene 2018; 37:697-709. [PMID: 29059164 PMCID: PMC5808099 DOI: 10.1038/onc.2017.358] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 08/07/2017] [Accepted: 08/12/2017] [Indexed: 12/13/2022]
Abstract
Mitochondrial dysregulation plays a central role in cancers and drives reactive oxygen species (ROS)-dependent tumor progression. We investigated the pro-tumoral roles of mitochondrial dynamics and altered intracellular ROS levels in pancreatic ductal adenocarcinoma (PDAC). We identified 'family with sequence similarity 49 member B' (FAM49B) as a mitochondria-localized protein that regulates mitochondrial fission and cancer progression. Silencing FAM49B in PDAC cells resulted in increased fission and mitochondrial ROS generation, which enhanced PDAC cell proliferation and invasion. Notably, FAM49B expression levels in PDAC cells were downregulated by the tumor microenvironment. Overall, the results of this study show that FAM49B acts as a suppressor of cancer cell proliferation and invasion in PDAC by regulating tumor mitochondrial redox reactions and metabolism.
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Affiliation(s)
- M S Chattaragada
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
| | - C Riganti
- Department of Oncology, University of Turin, Turin, Italy
| | - M Sassoe
- Department of Neurosciences, ‘Rita Levi Montalcini’, University of Turin, Turin, Italy
| | - M Principe
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
| | - M M Santamorena
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
| | - C Roux
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
| | - C Curcio
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
| | - A Evangelista
- Department of Clinical Epidemiology, Azienda Universitaria Ospedaliera Città della Salute e della Scienza and CPO Piemonte, Turin, Italy
| | - P Allavena
- Laboratory of Molecular Gastroenterology, Department of Gastroenterology, Humanitas Clinical and Research Center, Milan, Italy
| | - R Salvia
- Department of Surgery, The Pancreas Institute, University and Hospital Trust of Verona, Verona, Italy
| | - B Rusev
- Department of Pathology and Public Health & ARC-NET Research Center, University and Hospital Trust of Verona, Verona, Italy
| | - A Scarpa
- Department of Pathology and Public Health & ARC-NET Research Center, University and Hospital Trust of Verona, Verona, Italy
| | - P Cappello
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
- Molecular Biotechnology Center, University of Turin, Turin, Italy
| | - F Novelli
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
- Center for Experimental Research and Medical Studies, Azienda Universitaria Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy
- Molecular Biotechnology Center, University of Turin, Turin, Italy
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6
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Sotelo C. Molecular layer interneurons of the cerebellum: developmental and morphological aspects. CEREBELLUM (LONDON, ENGLAND) 2015; 14:534-56. [PMID: 25599913 DOI: 10.1007/s12311-015-0648-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
During the past 25 years, our knowledge on the development of basket and stellate cells (molecular layer interneurons [MLIs]) has completely changed, not only regarding their origin from the ventricular zone, corresponding to the primitive cerebellar neuroepithelium, instead of the external granular layer, but above all by providing an almost complete account of the genetic regulations (transcription factors and other genes) involved in their differentiation and synaptogenesis. Moreover, it has been shown that MLIs' precursors (dividing neuroblasts) and not young postmitotic neurons, as in other germinal neuroepithelia, leave the germinative zone and migrate all along a complex and lengthy path throughout the presumptive cerebellar white matter, which provides suitable niches exerting epigenetic influences on their ultimate neuronal identities. Recent studies carried out on the anatomical-functional properties of adult MLIs emphasize the importance of these interneurons in regulating PC inhibition, and point out the crucial role played by electrical synaptic transmission between MLIs as well as ephaptic interactions between them and Purkinje cells at the pinceaux level, in the regulation of this inhibition.
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Affiliation(s)
- Constantino Sotelo
- INSERM, UMRS_U968, Institut de la Vision, 17 Rue Moreau, Paris, 75012, France.
- Institut de la Vision, Sorbonne Université, UPMC Univ Paris 06, Paris, 75012, France.
- CNRS, UMR_7210, Paris, 75012, France.
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Miguel Hernández (UMH), Avenida Ramón y Cajal s/n, 03550, San Juan de Alicante, Spain.
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7
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Angliker N, Burri M, Zaichuk M, Fritschy JM, Rüegg MA. mTORC1 and mTORC2 have largely distinct functions in Purkinje cells. Eur J Neurosci 2015; 42:2595-612. [DOI: 10.1111/ejn.13051] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/13/2015] [Accepted: 08/14/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Nico Angliker
- Biozentrum; University of Basel; Klingelbergstrasse 70 CH-4056 Basel Switzerland
| | - Michael Burri
- Biozentrum; University of Basel; Klingelbergstrasse 70 CH-4056 Basel Switzerland
| | - Mariana Zaichuk
- Institute of Pharmacology and Toxicology; University of Zürich; Zürich Switzerland
| | - Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology; University of Zürich; Zürich Switzerland
| | - Markus A. Rüegg
- Biozentrum; University of Basel; Klingelbergstrasse 70 CH-4056 Basel Switzerland
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Abstract
Synapses of the mammalian CNS are diverse in size, structure, molecular composition, and function. Synapses in their myriad variations are fundamental to neural circuit development, homeostasis, plasticity, and memory storage. Unfortunately, quantitative analysis and mapping of the brain's heterogeneous synapse populations has been limited by the lack of adequate single-synapse measurement methods. Electron microscopy (EM) is the definitive means to recognize and measure individual synaptic contacts, but EM has only limited abilities to measure the molecular composition of synapses. This report describes conjugate array tomography (AT), a volumetric imaging method that integrates immunofluorescence and EM imaging modalities in voxel-conjugate fashion. We illustrate the use of conjugate AT to advance the proteometric measurement of EM-validated single-synapse analysis in a study of mouse cortex.
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Qu J, Liao YH, Kou ZZ, Wei YY, Huang J, Chen J, Yanagawa Y, Wu SX, Shi M, Li YQ. Puerarin alleviates noise-induced hearing loss via affecting PKCγ and GABAB receptor expression. J Neurol Sci 2015; 349:110-6. [DOI: 10.1016/j.jns.2014.12.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/01/2014] [Accepted: 12/28/2014] [Indexed: 10/24/2022]
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Zacchi P, Antonelli R, Cherubini E. Gephyrin phosphorylation in the functional organization and plasticity of GABAergic synapses. Front Cell Neurosci 2014; 8:103. [PMID: 24782709 PMCID: PMC3988358 DOI: 10.3389/fncel.2014.00103] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/22/2014] [Indexed: 11/13/2022] Open
Abstract
Gephyrin is a multifunctional scaffold protein essential for accumulation of inhibitory glycine and GABAA receptors at post-synaptic sites. The molecular events involved in gephyrin-dependent GABAA receptor clustering are still unclear. Evidence has been recently provided that gephyrin phosphorylation plays a key role in these processes. Gephyrin post-translational modifications have been shown to influence the structural remodeling of GABAergic synapses and synaptic plasticity by acting on post-synaptic scaffolding properties as well as stability. In addition, gephyrin phosphorylation and the subsequent phosphorylation-dependent recruitment of the chaperone molecule Pin1 provide a mechanism for the regulation of GABAergic signaling. Extensively characterized as pivotal enzyme controlling cell proliferation and differentiation, the prolyl-isomerase activity of Pin1 has been shown to regulate protein synthesis necessary to sustain the late phase of long-term potentiation at excitatory synapses, which suggests its involvement at synaptic sites. In this review we summarize the current state of knowledge of the signaling pathways responsible for gephyrin post-translational modifications. We will also outline future lines of research that might contribute to a better understanding of molecular mechanisms by which gephyrin regulates synaptic plasticity at GABAergic synapses.
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Affiliation(s)
- Paola Zacchi
- Department of Neurosciences, Scuola Internazionale Superiore di Studi Avanzati Trieste, Italy
| | - Roberta Antonelli
- Department of Neurosciences, Scuola Internazionale Superiore di Studi Avanzati Trieste, Italy
| | - Enrico Cherubini
- Department of Neurosciences, Scuola Internazionale Superiore di Studi Avanzati Trieste, Italy ; European Brain Research Institute Roma, Italy
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Snow WM, Anderson JE, Fry M. Regional and genotypic differences in intrinsic electrophysiological properties of cerebellar Purkinje neurons from wild-type and dystrophin-deficient mdx mice. Neurobiol Learn Mem 2014; 107:19-31. [DOI: 10.1016/j.nlm.2013.10.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 10/10/2013] [Accepted: 10/25/2013] [Indexed: 10/26/2022]
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12
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Pregno G, Frola E, Graziano S, Patrizi A, Bussolino F, Arese M, Sassoè-Pognetto M. Differential regulation of neurexin at glutamatergic and GABAergic synapses. Front Cell Neurosci 2013; 7:35. [PMID: 23576952 PMCID: PMC3616244 DOI: 10.3389/fncel.2013.00035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/18/2013] [Indexed: 11/30/2022] Open
Abstract
Neurexins (Nrxs) have emerged as potential determinants of synaptic specificity, but little is known about their localization at central synapses. Here we show that Nrxs have a remarkably selective localization at distinct types of glutamatergic synapses and we reveal an unexpected ontogenetic regulation of Nrx expression at GABAergic synapses. Our data indicate that synapses are specified by molecular interactions that involve both Nrx-dependent and Nrx-independent mechanisms. We propose that differences in the spatio-temporal profile of Nrx expression may contribute to specify the molecular identity of synapses.
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Affiliation(s)
- Giulia Pregno
- Department of Neuroscience, University of Turin Torino, Italy
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Frola E, Patrizi A, Goetz T, Medrihan L, Petrini EM, Barberis A, Wulff P, Wisden W, Sassoè-Pognetto M. Synaptic competition sculpts the development of GABAergic axo-dendritic but not perisomatic synapses. PLoS One 2013; 8:e56311. [PMID: 23457547 PMCID: PMC3572971 DOI: 10.1371/journal.pone.0056311] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 01/11/2013] [Indexed: 11/24/2022] Open
Abstract
The neurotransmitter GABA regulates many aspects of inhibitory synapse development. We tested the hypothesis that GABAA receptors (GABAARs) work together with the synaptic adhesion molecule neuroligin 2 (NL2) to regulate synapse formation in different subcellular compartments. We investigated mice (“γ2 knockdown mice”) with an engineered allele of the GABAAR γ2 subunit gene which produced a mosaic expression of synaptic GABAARs in neighboring neurons, causing a strong imbalance in synaptic inhibition. Deletion of the γ2 subunit did not abolish synapse formation or the targeting of NL2 to distinct types of perisomatic and axo-dendritic contacts. Thus synaptic localization of NL2 does not require synaptic GABAARs. However, loss of the γ2 subunit caused a selective decrease in the number of axo-dendritic synapses on cerebellar Purkinje cells and cortical pyramidal neurons, whereas perisomatic synapses were not significantly affected. Notably, γ2-positive cells had increased axo-dendritic innervation compared with both γ2-negative and wild-type counterparts. Moreover heterologous synapses on spines, that are found after total deletion of GABAARs from all Purkinje cells, were rare in cerebella of γ2 knockdown mice. These findings reveal a selective role of γ2 subunit-containing GABAARs in regulating synapse development in distinct subcellular compartments, and support the hypothesis that the refinement of axo-dendritic synapses is regulated by activity-dependent competition between neighboring neurons.
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Affiliation(s)
- Elena Frola
- Department of Neurosciences, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Annarita Patrizi
- Department of Neurosciences, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Thomas Goetz
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Lucian Medrihan
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Enrica Maria Petrini
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Andrea Barberis
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Peer Wulff
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - William Wisden
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- * E-mail: (WW); (MSP)
| | - Marco Sassoè-Pognetto
- Department of Neurosciences, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
- * E-mail: (WW); (MSP)
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14
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Ciccarelli A, Calza A, Panzanelli P, Concas A, Giustetto M, Sassoè-Pognetto M. Organization of GABAergic synaptic circuits in the rat ventral tegmental area. PLoS One 2012; 7:e46250. [PMID: 23056271 PMCID: PMC3466259 DOI: 10.1371/journal.pone.0046250] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 08/30/2012] [Indexed: 01/08/2023] Open
Abstract
The ventral tegmental area (VTA) is widely implicated in drug addiction and other psychiatric disorders. This brain region is densely populated by dopaminergic (DA) neurons and also contains a sparse population of γ-aminobutyric acid (GABA)ergic cells that regulate the activity of the principal neurons. Therefore, an in-depth knowledge of the organization of VTA GABAergic circuits and of the plasticity induced by drug consumption is essential for understanding the mechanisms by which drugs induce stable changes in brain reward circuits. Using immunohistochemistry, we provide a detailed description of the localization of major GABAA and GABAB receptor subunits in the rat VTA. We show that DA and GABAergic cells express both GABAA and GABAB receptors. However VTA neurons differ considerably in the expression of GABAA receptor subunits, as the α1 subunit is associated predominantly with non-DA cells, whereas the α3 subunit is present at low levels in both types of VTA neurons. Using an unbiased stereological method, we then demonstrate that α1-positive elements represent only a fraction of non-DA neurons and that the ratio of DA and non-DA cells is quite variable throughout the rostro-caudal extent of the VTA. Interestingly, DA and non-DA cells receive a similar density of perisomatic synapses, whereas axo-dendritic synapses are significantly more abundant in non-DA cells, indicating that local interneurons receive prominent GABAergic inhibition. These findings reveal a differential expression of GABA receptor subtypes in the two major categories of VTA neurons and provide an anatomical basis for interpreting the plasticity of inhibitory circuits induced by drug exposure.
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Affiliation(s)
- Alessandro Ciccarelli
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Arianna Calza
- Department of Experimental Biology and Center of Excellence for the Neurobiology of Dependence, University of Cagliari, Cagliari, Italy
| | - Patrizia Panzanelli
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Alessandra Concas
- Department of Experimental Biology and Center of Excellence for the Neurobiology of Dependence, University of Cagliari, Cagliari, Italy
| | - Maurizio Giustetto
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Marco Sassoè-Pognetto
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
- * E-mail:
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15
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Setting the time course of inhibitory synaptic currents by mixing multiple GABA(A) receptor α subunit isoforms. J Neurosci 2012; 32:5853-67. [PMID: 22539847 DOI: 10.1523/jneurosci.6495-11.2012] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The kinetics of IPSCs influence many neuronal processes, such as the frequencies of oscillations and the duration of shunting inhibition. The subunit composition of recombinant GABA(A) receptors (GABA(A)Rs) strongly affects the deactivation kinetics of GABA-evoked currents. However, for GABAergic synapses, the relationship between subunit composition and IPSC decay is less clear. Here we addressed this by combining whole-cell recordings of miniature IPSCs (mIPSCs) and quantitative immunolocalization of synaptic GABA(A)R subunits. In cerebellar stellate, thalamic relay, and main olfactory bulb (MOB) deep short-axon cells of Wistar rats, the only synaptic α subunit was α1, and zolpidem-sensitive mIPSCs had weighted decay time constants (τ(w)) of 4-6 ms. Nucleus reticularis thalami neurons expressed only α3 as the synaptic α subunit and exhibited slow (τ(w) = 28 ms), zolpidem-insensitive mIPSCs. By contrast, MOB external tufted cells contained two α subunit types (α1 and α3) at their synapses. Quantitative analysis of multiple immunolabeled images revealed small within-cell, but large between-cell, variability in synaptic α1/α3 ratios. This corresponded to large cell-to-cell variability in the decay (τ(w) = 3-30 ms) and zolpidem sensitivity of mIPSCs. Currents evoked by rapid application of GABA to patches excised from HEK cells expressing different mixtures of α1 and α3 subunits displayed highly variable deactivation times that correlated with the α1/α3 cDNA ratio. Our results demonstrate that diversity in the decay of IPSCs can be generated by varying the expression of different GABA(A)R subunits that alone confer different decay kinetics, allowing the time course of inhibition to be tuned to individual cellular requirements.
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16
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Developmental switching of perisomatic innervation from climbing fibers to basket cell fibers in cerebellar Purkinje cells. J Neurosci 2012; 31:16916-27. [PMID: 22114262 DOI: 10.1523/jneurosci.2396-11.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In early postnatal development, perisomatic innervation of cerebellar Purkinje cells (PCs) switches from glutamatergic climbing fibers (CFs) to GABAergic basket cell fibers (BFs). Here we examined the switching process in C57BL/6 mice. At postnatal day 7 (P7), most perisomatic synapses were formed by CFs on to somatic spines. The density of CF-spine synapses peaked at P9, when pericellular nest around PCs by CFs was most developed, and CF-spine synapses constituted 88% of the total perisomatic synapses. Thereafter, CF-spine synapses dropped to 63% at P12, 6% at P15, and <1% at P20, whereas BF synapses increased reciprocally. During the switching period, a substantial number of BF synapses existed as BF-spine synapses (37% of the total perisomatic synapses at P15), and free spines surrounded by BFs or Bergmann glia also emerged. By P20, BF-spine synapses and free spines virtually disappeared, and BF-soma synapses became predominant (88%), thus attaining the adult pattern of perisomatic innervation. Parallel with the presynaptic switching, postsynaptic receptor phenotype also switched from glutamatergic to GABAergic. In the active switching period, particularly at P12, fragmental clusters of AMPA-type glutamate receptor were juxtaposed with those of GABA(A) receptor. When examined with serial ultrathin sections, immunogold labeling for glutamate and GABA(A) receptors was often clustered beneath single BF terminals. These results suggest that a considerable fraction of somatic spines is succeeded from CFs to BFs and Bergmann glia in the early postnatal period, and that the switching of postsynaptic receptor phenotypes mainly proceeds under the coverage of BF terminals.
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Patrizi A, Viltono L, Frola E, Harvey K, Harvey RJ, Sassoè-Pognetto M. Selective localization of collybistin at a subset of inhibitory synapses in brain circuits. J Comp Neurol 2011; 520:130-41. [DOI: 10.1002/cne.22702] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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18
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Sassoè-Pognetto M, Frola E, Pregno G, Briatore F, Patrizi A. Understanding the molecular diversity of GABAergic synapses. Front Cell Neurosci 2011; 5:4. [PMID: 21713106 PMCID: PMC3112311 DOI: 10.3389/fncel.2011.00004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 05/23/2011] [Indexed: 01/17/2023] Open
Abstract
GABAergic synapses exhibit a high degree of subcellular and molecular specialization, which contrasts with their apparent simplicity in ultrastructural appearance. Indeed, when observed in the electron microscope, GABAergic synapses fit in the symmetric, or Gray’s type II category, being characterized by a relatively simple postsynaptic specialization. The inhibitory postsynaptic density cannot be readily isolated, and progress in understanding its molecular composition has lagged behind that of excitatory synapses. However, recent studies have brought significant progress in the identification of new synaptic proteins, revealing an unexpected complexity in the molecular machinery that regulates GABAergic synaptogenesis. In this article, we provide an overview of the molecular diversity of GABAergic synapses, and we consider how synapse specificity may be encoded by selective trans-synaptic interactions between pre- and postsynaptic adhesion molecules and secreted factors that reside in the synaptic cleft. We also discuss the importance of developing cataloguing tools that could be used to decipher the molecular diversity of synapses and to predict alterations of inhibitory transmission in the course of neurological diseases.
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Affiliation(s)
- Marco Sassoè-Pognetto
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin Torino, Italy
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19
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Li Y, Serwanski DR, Miralles CP, Fiondella CG, Loturco JJ, Rubio ME, De Blas AL. Synaptic and nonsynaptic localization of protocadherin-gammaC5 in the rat brain. J Comp Neurol 2010; 518:3439-63. [PMID: 20589908 DOI: 10.1002/cne.22390] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
It has been proposed that gamma-protocadherins (Pcdh-gammas) are involved in the establishment of specific patterns of neuronal connectivity. Contrary to the other Pcdh-gammas, which are expressed in the embryo, Pcdh-gammaC5 is expressed postnatally in the brain, coinciding with the peak of synaptogenesis. We have developed an antibody specific for Pcdh-gammaC5 to study the expression and localization of Pcdh-gammaC5 in brain. Pcdh-gammaC5 is highly expressed in the olfactory bulb, corpus striatum, dentate gyrus, CA1 region of the hippocampus, layers I and II of the cerebral cortex, and molecular layer of the cerebellum. Pcdh-gammaC5 is expressed in both neurons and astrocytes. In hippocampal neuronal cultures, and in the absence of astrocytes, a significant percentage of synapses, more GABAergic than glutamatergic, have associated Pcdh-gammaC5 clusters. Some GABAergic axons show Pcdh-gammaC5 in the majority of their synapses. Nevertheless, many Pcdh-gammaC5 clusters are not associated with synapses. In the brain, significant numbers of Pcdh-gammaC5 clusters are located at contact points between neurons and astrocytes. Electron microscopic immunocytochemistry of the rat brain shows that 1) Pcdh-gammaC5 is present in some GABAergic and glutamatergic synapses both pre- and postsynaptically; 2) Pcdh-gammaC5 is also extrasynaptically localized in membranes and in cytoplasmic organelles of neurons and astrocytes; and 3) Pcdh-gammaC5 is also localized in perisynaptic astrocyte processes. The results support the notions that 1) Pcdh-gammaC5 plays a role in synaptic specificity and/or synaptic maturation and 2) Pcdh-gammaC5 is involved in neuron-neuron synaptic interactions and in neuron-astrocyte interactions, including perisynaptic neuron-astrocyte interactions.
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Affiliation(s)
- Yanfang Li
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269-3156, USA
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20
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Quantitative organization of GABAergic synapses in the molecular layer of the mouse cerebellar cortex. PLoS One 2010; 5:e12119. [PMID: 20711348 PMCID: PMC2920831 DOI: 10.1371/journal.pone.0012119] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 07/20/2010] [Indexed: 11/26/2022] Open
Abstract
In the cerebellar cortex, interneurons of the molecular layer (stellate and basket cells) provide GABAergic input to Purkinje cells, as well as to each other and possibly to other interneurons. GABAergic inhibition in the molecular layer has mainly been investigated at the interneuron to Purkinje cell synapse. In this study, we used complementary subtractive strategies to quantitatively assess the ratio of GABAergic synapses on Purkinje cell dendrites versus those on interneurons. We generated a mouse model in which the GABAA receptor α1 subunit (GABAARα1) was selectively removed from Purkinje cells using the Cre/loxP system. Deletion of the α1 subunit resulted in a complete loss of GABAAR aggregates from Purkinje cells, allowing us to determine the density of GABAAR clusters in interneurons. In a complementary approach, we determined the density of GABA synapses impinging on Purkinje cells using α-dystroglycan as a specific marker of inhibitory postsynaptic sites. Combining these inverse approaches, we found that synapses received by interneurons represent approximately 40% of all GABAergic synapses in the molecular layer. Notably, this proportion was stable during postnatal development, indicating synchronized synaptogenesis. Based on the pure quantity of GABAergic synapses onto interneurons, we propose that mutual inhibition must play an important, yet largely neglected, computational role in the cerebellar cortex.
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21
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Lappe-Siefke C, Loebrich S, Hevers W, Waidmann OB, Schweizer M, Fehr S, Fritschy JM, Dikic I, Eilers J, Wilson SM, Kneussel M. The ataxia (axJ) mutation causes abnormal GABAA receptor turnover in mice. PLoS Genet 2009; 5:e1000631. [PMID: 19759851 PMCID: PMC2744266 DOI: 10.1371/journal.pgen.1000631] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Accepted: 08/04/2009] [Indexed: 11/26/2022] Open
Abstract
Ataxia represents a pathological coordination failure that often involves functional disturbances in cerebellar circuits. Purkinje cells (PCs) characterize the only output neurons of the cerebellar cortex and critically participate in regulating motor coordination. Although different genetic mutations are known that cause ataxia, little is known about the underlying cellular mechanisms. Here we show that a mutated axJ gene locus, encoding the ubiquitin-specific protease 14 (Usp14), negatively influences synaptic receptor turnover. AxJ mouse mutants, characterized by cerebellar ataxia, display both increased GABAA receptor (GABAAR) levels at PC surface membranes accompanied by enlarged IPSCs. Accordingly, we identify physical interaction of Usp14 and the GABAAR α1 subunit. Although other currently unknown changes might be involved, our data show that ubiquitin-dependent GABAAR turnover at cerebellar synapses contributes to axJ-mediated behavioural impairment. Cerebellar ataxia describes a combination of motor symptoms and uncoordinated movements that originates from various hereditary and non-hereditary diseases. Although functional disturbances of cerebellar inhibitory output signals are thought to cause ataxia, the underlying molecular mechanisms are barely understood and medical treatment therefore remains difficult. We analysed a behavioural abnormality up to the molecular level in a mouse mutant (axJ) representing a model for ataxia. The axJ mutation reduces the expression level of a ubiquitin protease (Usp14) leading to an abnormal turnover of neurotransmitter receptors. Despite other yet unknown changes in axJ mutants, our data show that intracellular protein turnover contributes to a motor behavioural syndrome.
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Affiliation(s)
- Corinna Lappe-Siefke
- Zentrum für Molekulare Neurobiologie Hamburg, Universität Hamburg, Hamburg, Germany
| | - Sven Loebrich
- Zentrum für Molekulare Neurobiologie Hamburg, Universität Hamburg, Hamburg, Germany
| | - Wulf Hevers
- Carl-Ludwig-Institut für Physiologie, Universität Leipzig, Leipzig, Germany
| | - Oliver B. Waidmann
- Institut für Biochemie II, Universität Frankfurt, Frankfurt, Germany
- Klinik für Innere Medizin 1, Schwerpunkt Gastroenterologie und Hepatologie, Universität Frankfurt, Frankfurt, Germany
| | - Michaela Schweizer
- Zentrum für Molekulare Neurobiologie Hamburg, Universität Hamburg, Hamburg, Germany
| | - Susanne Fehr
- Zentrum für Molekulare Neurobiologie Hamburg, Universität Hamburg, Hamburg, Germany
| | - Jean-Marc Fritschy
- Institute of Pharmacology und Toxicology, University of Zurich, Zurich, Switzerland
| | - Ivan Dikic
- Institut für Biochemie II, Universität Frankfurt, Frankfurt, Germany
| | - Jens Eilers
- Carl-Ludwig-Institut für Physiologie, Universität Leipzig, Leipzig, Germany
| | - Scott M. Wilson
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Matthias Kneussel
- Zentrum für Molekulare Neurobiologie Hamburg, Universität Hamburg, Hamburg, Germany
- * E-mail:
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22
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The Treasury of the Commons: Making Use of Public Gene Expression Resources to Better Characterize the Molecular Diversity of Inhibitory Interneurons in the Cerebellar Cortex. THE CEREBELLUM 2009; 8:477-89. [DOI: 10.1007/s12311-009-0124-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 06/09/2009] [Indexed: 11/25/2022]
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Papadopoulos T, Eulenburg V, Reddy-Alla S, Mansuy IM, Li Y, Betz H. Collybistin is required for both the formation and maintenance of GABAergic postsynapses in the hippocampus. Mol Cell Neurosci 2008; 39:161-9. [DOI: 10.1016/j.mcn.2008.06.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/28/2008] [Accepted: 06/10/2008] [Indexed: 11/16/2022] Open
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