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Bats C, Coombs ID, Farrant M, Cull-Candy SG. α-Bungarotoxin labelling of AMPA receptor-associated TARPs in living neurons. Neuroscience 2024:S0306-4522(24)00440-8. [PMID: 39209103 DOI: 10.1016/j.neuroscience.2024.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/30/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
In mammalian central neurons AMPARs are clustered at glutamatergic synapses where they mediate fast excitatory transmission. In addition to four pore-forming subunits (GluA1-4), AMPARs contain auxiliary transmembrane AMPAR regulatory proteins (γ2, γ3, γ4, γ5, γ7 or γ8) whose incorporation can vary between neuron types, brain regions, and stages of development. As well as modulating the functional properties of AMPARs, these auxiliary subunits play a central role in AMPAR trafficking. Directly visualizing TARPs could therefore provide a valuable insight into mechanisms underlying these processes. Although antibodies are routinely used for the detection of surface proteins, our experience suggests anti-TARP antibodies are too bulky to access their target, possibly due to close interactions between the extracellular domains of TARP and AMPAR subunits. We therefore assessed the utility of a small monovalent probe - fluorescent α-bungarotoxin (α-Btx) - for TARP labelling in living neurons. We inserted the bungarotoxin binding site (BBS) within the extracellular domain of TARPs to enable their detection in cells exposed to fluorescent α-Btx. Focusing on the prototypical TARP γ2, we demonstrate that the small size of fluorescent α-Btx allows it to bind to the BBS-tagged TARP when associated with AMPARs. Importantly, labelled γ2 enhances AMPAR function in the same way as unmodified γ2. In living neurons, fluorescent α-Btx-labelled γ2 associates with AMPAR clusters at synapses. As a proof-of-principle, we employed our method to compare the surface trafficking of γ2 and γ7 in cerebellar stellate neurons. Our approach provides a simple way to visualize TARPs within AMPARs in living cells.
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Affiliation(s)
- Cecile Bats
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Ian D Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
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2
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Bessa-Neto D, Choquet D. Molecular mechanisms of AMPAR reversible stabilization at synapses. Mol Cell Neurosci 2023; 125:103856. [PMID: 37105372 DOI: 10.1016/j.mcn.2023.103856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 04/29/2023] Open
Abstract
In the central nervous system, glutamatergic synapses play a central role in the regulation of excitatory neuronal transmission. With the membrane-associated guanylate kinase (MAGUK) family of proteins as their structuring scaffold, glutamatergic receptors serve as the powerhouse of glutamatergic synapses. Glutamatergic receptors can be categorized as metabotropic and ionotropic receptors. The latter are then categorized into N-methyl-d-aspartate, kainate receptors, and α-amino-3-hydroxy-5-methyl-isoxazole-propionic acid receptors (AMPARs). Over the past two decades, genetic tagging technology and super-resolution microscopy have been of the utmost importance to unravel how the different receptors are organized at glutamatergic synapses. At the plasma membrane, receptors are highly mobile but show reduced mobility when at synaptic sites. This partial immobilization of receptors at synaptic sites is attributed to the stabilization/anchoring of receptors with the postsynaptic MAGUK proteins and auxiliary proteins, and presynaptic proteins. These partial immobilizations and localization of glutamatergic receptors within the synaptic sites are fundamental for proper basal transmission and synaptic plasticity. Perturbations of the stabilization of glutamatergic receptors are often associated with cognitive deficits. In this review, we describe the proposed mechanisms for synaptic localization and stabilization of AMPARs, the major players of fast excitatory transmission in the central nervous system.
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Affiliation(s)
- Diogo Bessa-Neto
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000 Bordeaux, France
| | - Daniel Choquet
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000 Bordeaux, France; Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France.
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3
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Coombs I, Bats C, Sexton CA, Studniarczyk D, Cull-Candy SG, Farrant M. Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM. eLife 2023; 12:e66765. [PMID: 37042655 PMCID: PMC10168695 DOI: 10.7554/elife.66765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/11/2023] [Indexed: 04/13/2023] Open
Abstract
Calcium-permeable AMPA-type glutamate receptors (CP-AMPARs) contribute to many forms of synaptic plasticity and pathology. They can be distinguished from GluA2-containing calcium-impermeable AMPARs by the inward rectification of their currents, which reflects voltage-dependent channel block by intracellular spermine. However, the efficacy of this weakly permeant blocker is differentially altered by the presence of AMPAR auxiliary subunits - including transmembrane AMPAR regulatory proteins, cornichons, and GSG1L - which are widely expressed in neurons and glia. This complicates the interpretation of rectification as a measure of CP-AMPAR expression. Here, we show that the inclusion of the spider toxin analog 1-naphthylacetyl spermine (NASPM) in the intracellular solution results in a complete block of GluA1-mediated outward currents irrespective of the type of associated auxiliary subunit. In neurons from GluA2-knockout mice expressing only CP-AMPARs, intracellular NASPM, unlike spermine, completely blocks outward synaptic currents. Thus, our results identify a functional measure of CP-AMPARs, that is unaffected by their auxiliary subunit content.
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Affiliation(s)
- Ian Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Cécile Bats
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Craig A Sexton
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Dorota Studniarczyk
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
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4
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Namkung H, Yukitake H, Fukudome D, Lee BJ, Tian M, Ursini G, Saito A, Lam S, Kannan S, Srivastava R, Niwa M, Sharma K, Zandi P, Jaaro-Peled H, Ishizuka K, Chatterjee N, Huganir RL, Sawa A. The miR-124-AMPAR pathway connects polygenic risks with behavioral changes shared between schizophrenia and bipolar disorder. Neuron 2023; 111:220-235.e9. [PMID: 36379214 PMCID: PMC10183200 DOI: 10.1016/j.neuron.2022.10.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 08/16/2022] [Accepted: 10/20/2022] [Indexed: 11/16/2022]
Abstract
Schizophrenia (SZ) and bipolar disorder (BP) are highly heritable major psychiatric disorders that share a substantial portion of genetic risk as well as their clinical manifestations. This raises a fundamental question of whether, and how, common neurobiological pathways translate their shared polygenic risks into shared clinical manifestations. This study shows the miR-124-3p-AMPAR pathway as a key common neurobiological mediator that connects polygenic risks with behavioral changes shared between these two psychotic disorders. We discovered the upregulation of miR-124-3p in neuronal cells and the postmortem prefrontal cortex from both SZ and BP patients. Intriguingly, the upregulation is associated with the polygenic risks shared between these two disorders. Seeking mechanistic dissection, we generated a mouse model that upregulates miR-124-3p in the medial prefrontal cortex. We demonstrated that the upregulation of miR-124-3p increases GRIA2-lacking calcium-permeable AMPARs and perturbs AMPAR-mediated excitatory synaptic transmission, leading to deficits in the behavioral dimensions shared between SZ and BP.
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Affiliation(s)
- Ho Namkung
- Department of Biomedical Engineering, Baltimore, MD, USA; Department of Psychiatry, Baltimore, MD, USA
| | | | | | - Brian J Lee
- Department of Psychiatry, Baltimore, MD, USA
| | | | - Gianluca Ursini
- Department of Psychiatry, Baltimore, MD, USA; Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | | | - Shravika Lam
- Department of Psychiatry, Baltimore, MD, USA; Department of Neuroscience, Baltimore, MD, USA
| | - Suvarnambiga Kannan
- Department of Psychiatry, Baltimore, MD, USA; Department of Mental Health, Baltimore, MD, USA
| | | | - Minae Niwa
- Department of Psychiatry, Baltimore, MD, USA
| | - Kamal Sharma
- Department of Psychiatry, Baltimore, MD, USA; Department of Neuroscience, Baltimore, MD, USA
| | - Peter Zandi
- Department of Psychiatry, Baltimore, MD, USA; Department of Mental Health, Baltimore, MD, USA; Department of Epidemiology, Baltimore, MD, USA
| | | | | | - Nilanjan Chatterjee
- Department of Epidemiology, Baltimore, MD, USA; Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Richard L Huganir
- Department of Psychiatry, Baltimore, MD, USA; Department of Neuroscience, Baltimore, MD, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Akira Sawa
- Department of Biomedical Engineering, Baltimore, MD, USA; Department of Psychiatry, Baltimore, MD, USA; Department of Neuroscience, Baltimore, MD, USA; Department of Pharmacology, Baltimore, MD, USA; Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Mental Health, Baltimore, MD, USA.
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5
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Ahmed KT, Amin MR, Razmara P, Roy B, Cai R, Tang J, Chen XZ, Ali DW. Expression and Development of TARP γ-4 in Embryonic Zebrafish. Dev Neurosci 2022; 44:518-531. [PMID: 35728564 DOI: 10.1159/000525578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 05/19/2022] [Indexed: 11/19/2022] Open
Abstract
Fast excitatory synaptic transmission in the CNS is mediated by the neurotransmitter glutamate, binding to and activating AMPA receptors (AMPARs). AMPARs are known to interact with auxiliary proteins that modulate their behavior. One such family of proteins is the transmembrane AMPAR-related proteins, known as TARPs. Little is known about the role of TARPs during development or about their function in nonmammalian organisms. Here, we report on the presence of TARP γ-4 in developing zebrafish. We find that zebrafish express 2 forms of TARP γ-4: γ-4a and γ-4b as early as 12 h post-fertilization. Sequence analysis shows that both γ-4a and γ-4b shows great level of variation particularly in the intracellular C-terminal domain compared to rat, mouse, and human γ-4. RT-qPCR showed a gradual increase in the expression of γ-4a throughout the first 5 days of development, whereas γ-4b levels were constant until day 5 when levels increased significantly. Knockdown of TARP γ-4a and γ-4b via either splice-blocking morpholinos or translation-blocking morpholinos resulted in embryos that exhibited deficits in C-start escape responses, showing reduced C-bend angles. Morphant larvae displayed reduced bouts of swimming. Whole-cell patch-clamp recordings of AMPAR-mediated currents from Mauthner cells showed a reduction in the frequency of mEPCs but no change in amplitude or kinetics. Together, these results suggest that γ-4a and γ-4b are required for proper neuronal development.
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Affiliation(s)
- Kazi Tanveer Ahmed
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Md Ruhul Amin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Parastoo Razmara
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Birbickram Roy
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Ruiqi Cai
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Xing-Zhen Chen
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Declan William Ali
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
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6
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Hansen KB, Wollmuth LP, Bowie D, Furukawa H, Menniti FS, Sobolevsky AI, Swanson GT, Swanger SA, Greger IH, Nakagawa T, McBain CJ, Jayaraman V, Low CM, Dell'Acqua ML, Diamond JS, Camp CR, Perszyk RE, Yuan H, Traynelis SF. Structure, Function, and Pharmacology of Glutamate Receptor Ion Channels. Pharmacol Rev 2021; 73:298-487. [PMID: 34753794 PMCID: PMC8626789 DOI: 10.1124/pharmrev.120.000131] [Citation(s) in RCA: 256] [Impact Index Per Article: 85.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many physiologic effects of l-glutamate, the major excitatory neurotransmitter in the mammalian central nervous system, are mediated via signaling by ionotropic glutamate receptors (iGluRs). These ligand-gated ion channels are critical to brain function and are centrally implicated in numerous psychiatric and neurologic disorders. There are different classes of iGluRs with a variety of receptor subtypes in each class that play distinct roles in neuronal functions. The diversity in iGluR subtypes, with their unique functional properties and physiologic roles, has motivated a large number of studies. Our understanding of receptor subtypes has advanced considerably since the first iGluR subunit gene was cloned in 1989, and the research focus has expanded to encompass facets of biology that have been recently discovered and to exploit experimental paradigms made possible by technological advances. Here, we review insights from more than 3 decades of iGluR studies with an emphasis on the progress that has occurred in the past decade. We cover structure, function, pharmacology, roles in neurophysiology, and therapeutic implications for all classes of receptors assembled from the subunits encoded by the 18 ionotropic glutamate receptor genes. SIGNIFICANCE STATEMENT: Glutamate receptors play important roles in virtually all aspects of brain function and are either involved in mediating some clinical features of neurological disease or represent a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of this class of receptors will advance our understanding of many aspects of brain function at molecular, cellular, and system levels and provide new opportunities to treat patients.
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Affiliation(s)
- Kasper B Hansen
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Lonnie P Wollmuth
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Derek Bowie
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Hiro Furukawa
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Frank S Menniti
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Alexander I Sobolevsky
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Geoffrey T Swanson
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Sharon A Swanger
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Ingo H Greger
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Terunaga Nakagawa
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chris J McBain
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Vasanthi Jayaraman
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chian-Ming Low
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Mark L Dell'Acqua
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Jeffrey S Diamond
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chad R Camp
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Riley E Perszyk
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Hongjie Yuan
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Stephen F Traynelis
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
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Guo C, Ma YY. Calcium Permeable-AMPA Receptors and Excitotoxicity in Neurological Disorders. Front Neural Circuits 2021; 15:711564. [PMID: 34483848 PMCID: PMC8416103 DOI: 10.3389/fncir.2021.711564] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 07/23/2021] [Indexed: 12/13/2022] Open
Abstract
Excitotoxicity is one of the primary mechanisms of cell loss in a variety of diseases of the central and peripheral nervous systems. Other than the previously established signaling pathways of excitotoxicity, which depend on the excessive release of glutamate from axon terminals or over-activation of NMDA receptors (NMDARs), Ca2+ influx-triggered excitotoxicity through Ca2+-permeable (CP)-AMPA receptors (AMPARs) is detected in multiple disease models. In this review, both acute brain insults (e.g., brain trauma or spinal cord injury, ischemia) and chronic neurological disorders, including Epilepsy/Seizures, Huntington’s disease (HD), Parkinson’s disease (PD), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), chronic pain, and glaucoma, are discussed regarding the CP-AMPAR-mediated excitotoxicity. Considering the low expression or absence of CP-AMPARs in most cells, specific manipulation of the CP-AMPARs might be a more plausible strategy to delay the onset and progression of pathological alterations with fewer side effects than blocking NMDARs.
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Affiliation(s)
- Changyong Guo
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yao-Ying Ma
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
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Li L, Chen SR, Zhou MH, Wang L, Li DP, Chen H, Lee G, Jayaraman V, Pan HL. α2δ-1 switches the phenotype of synaptic AMPA receptors by physically disrupting heteromeric subunit assembly. Cell Rep 2021; 36:109396. [PMID: 34289359 PMCID: PMC8353586 DOI: 10.1016/j.celrep.2021.109396] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 04/19/2021] [Accepted: 06/22/2021] [Indexed: 11/22/2022] Open
Abstract
Many neurological disorders show an increased prevalence of GluA2-lacking, Ca2+-permeable AMPA receptors (CP-AMPARs), which dramatically alters synaptic function. However, the molecular mechanism underlying this distinct synaptic plasticity remains enigmatic. Here, we show that nerve injury potentiates postsynaptic, but not presynaptic, CP-AMPARs in the spinal dorsal horn via α2δ-1. Overexpressing α2δ-1, previously regarded as a Ca2+ channel subunit, augments CP-AMPAR levels at the cell surface and synapse. Mechanistically, α2δ-1 physically interacts with both GluA1 and GluA2 via its C terminus, inhibits the GluA1/GluA2 heteromeric assembly, and increases GluA2 retention in the endoplasmic reticulum. Consequently, α2δ-1 diminishes the availability and synaptic expression of GluA1/GluA2 heterotetramers in the spinal cord in neuropathic pain. Inhibiting α2δ-1 with gabapentin or disrupting the α2δ-1-AMPAR complex fully restores the intracellular assembly and synaptic dominance of heteromeric GluA1/GluA2 receptors. Thus, α2δ-1 is a pivotal AMPAR-interacting protein that controls the subunit composition and Ca2+ permeability of postsynaptic AMPARs.
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Affiliation(s)
- Lingyong Li
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shao-Rui Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Meng-Hua Zhou
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Li Wang
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - De-Pei Li
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Medicine, University of Missouri School of Medicine, Columbia, MO 65211, USA
| | - Hong Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Garam Lee
- Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Hui-Lin Pan
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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9
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Matthews PM, Pinggera A, Kampjut D, Greger IH. Biology of AMPA receptor interacting proteins - From biogenesis to synaptic plasticity. Neuropharmacology 2021; 197:108709. [PMID: 34271020 DOI: 10.1016/j.neuropharm.2021.108709] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/19/2021] [Accepted: 07/08/2021] [Indexed: 12/19/2022]
Abstract
AMPA-type glutamate receptors mediate the majority of excitatory synaptic transmission in the central nervous system. Their signaling properties and abundance at synapses are both crucial determinants of synapse efficacy and plasticity, and are therefore under sophisticated control. Unique to this ionotropic glutamate receptor (iGluR) is the abundance of interacting proteins that contribute to its complex regulation. These include transient interactions with the receptor cytoplasmic tail as well as the N-terminal domain locating to the synaptic cleft, both of which are involved in AMPAR trafficking and receptor stabilization at the synapse. Moreover, an array of transmembrane proteins operate as auxiliary subunits that in addition to receptor trafficking and stabilization also substantially impact AMPAR gating and pharmacology. Here, we provide an overview of the catalogue of AMPAR interacting proteins, and how they contribute to the complex biology of this central glutamate receptor.
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Affiliation(s)
- Peter M Matthews
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Alexandra Pinggera
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Domen Kampjut
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK.
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10
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Hardt S, Tascio D, Passlick S, Timmermann A, Jabs R, Steinhäuser C, Seifert G. Auxiliary Subunits Control Function and Subcellular Distribution of AMPA Receptor Complexes in NG2 Glia of the Developing Hippocampus. Front Cell Neurosci 2021; 15:669717. [PMID: 34177466 PMCID: PMC8222826 DOI: 10.3389/fncel.2021.669717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Synaptic and axonal glutamatergic signaling to NG2 glia in white matter is critical for the cells' differentiation and activity dependent myelination. However, in gray matter the impact of neuron-to-NG2 glia signaling is still elusive, because most of these cells keep their non-myelinating phenotype throughout live. Early in postnatal development, hippocampal NG2 glia express AMPA receptors with a significant Ca2+ permeability allowing for plasticity of the neuron-glia synapses, but whether this property changes by adulthood is not known. Moreover, it is unclear whether NG2 glia express auxiliary transmembrane AMPA receptor related proteins (TARPs), which modify AMPA receptor properties, including their Ca2+ permeability. Through combined molecular and functional analyses, here we show that hippocampal NG2 glia abundantly express TARPs γ4, γ7, and γ8 as well as cornichon (CNIH)-2. TARP γ8 undergoes profound downregulation during development. Receptors of adult NG2 glia showed an increased sensitivity to blockers of Ca2+ permeable AMPA receptors, but this increase mainly concerned receptors located close to the soma. Evoked synaptic currents of NG2 glia were also sensitive to blockers of Ca2+ permeable AMPA receptors. The presence of AMPA receptors with varying Ca2+ permeability during postnatal maturation may be important for the cells' ability to sense and respond to local glutamatergic activity and for regulating process motility, differentiation, and proliferation.
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Affiliation(s)
- Stefan Hardt
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dario Tascio
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Stefan Passlick
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Aline Timmermann
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ronald Jabs
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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11
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Cull‐Candy SG, Farrant M. Ca 2+ -permeable AMPA receptors and their auxiliary subunits in synaptic plasticity and disease. J Physiol 2021; 599:2655-2671. [PMID: 33533533 PMCID: PMC8436767 DOI: 10.1113/jp279029] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/28/2021] [Indexed: 12/14/2022] Open
Abstract
AMPA receptors are tetrameric glutamate-gated ion channels that mediate a majority of fast excitatory neurotransmission in the brain. They exist as calcium-impermeable (CI-) and calcium-permeable (CP-) subtypes, the latter of which lacks the GluA2 subunit. CP-AMPARs display an array of distinctive biophysical and pharmacological properties that allow them to be functionally identified. This has revealed that they play crucial roles in diverse forms of central synaptic plasticity. Here we summarise the functional hallmarks of CP-AMPARs and describe how these are modified by the presence of auxiliary subunits that have emerged as pivotal regulators of AMPARs. A lasting change in the prevalence of GluA2-containing AMPARs, and hence in the fraction of CP-AMPARs, is a feature in many maladaptive forms of synaptic plasticity and neurological disorders. These include modifications of glutamatergic transmission induced by inflammatory pain, fear conditioning, cocaine exposure, and anoxia-induced damage in neurons and glia. Furthermore, defective RNA editing of GluA2 can cause altered expression of CP-AMPARs and is implicated in motor neuron damage (amyotrophic lateral sclerosis) and the proliferation of cells in malignant gliomas. A number of the players involved in CP-AMPAR regulation have been identified, providing useful insight into interventions that may prevent the aberrant CP-AMPAR expression. Furthermore, recent molecular and pharmacological developments, particularly the discovery of TARP subtype-selective drugs, offer the exciting potential to modify some of the harmful effects of increased CP-AMPAR prevalence in a brain region-specific manner.
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Affiliation(s)
- Stuart G. Cull‐Candy
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonGower StreetLondonWC1E 6BTUK
| | - Mark Farrant
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonGower StreetLondonWC1E 6BTUK
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12
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Dolgacheva LP, Tuleukhanov ST, Zinchenko VP. Participation of Ca2+-Permeable AMPA Receptors in Synaptic Plasticity. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2020. [DOI: 10.1134/s1990747820030046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Miguez-Cabello F, Sánchez-Fernández N, Yefimenko N, Gasull X, Gratacòs-Batlle E, Soto D. AMPAR/TARP stoichiometry differentially modulates channel properties. eLife 2020; 9:53946. [PMID: 32452760 PMCID: PMC7299370 DOI: 10.7554/elife.53946] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 05/24/2020] [Indexed: 11/15/2022] Open
Abstract
AMPARs control fast synaptic communication between neurons and their function relies on auxiliary subunits, which importantly modulate channel properties. Although it has been suggested that AMPARs can bind to TARPs with variable stoichiometry, little is known about the effect that this stoichiometry exerts on certain AMPAR properties. Here we have found that AMPARs show a clear stoichiometry-dependent modulation by the prototypical TARP γ2 although the receptor still needs to be fully saturated with γ2 to show some typical TARP-induced characteristics (i.e. an increase in channel conductance). We also uncovered important differences in the stoichiometric modulation between calcium-permeable and calcium-impermeable AMPARs. Moreover, in heteromeric AMPARs, γ2 positioning in the complex is important to exert certain TARP-dependent features. Finally, by comparing data from recombinant receptors with endogenous AMPAR currents from mouse cerebellar granule cells, we have determined a likely presence of two γ2 molecules at somatic receptors in this cell type.
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Affiliation(s)
- Federico Miguez-Cabello
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Nuria Sánchez-Fernández
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Natalia Yefimenko
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Xavier Gasull
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Esther Gratacòs-Batlle
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - David Soto
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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14
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Paul BK, Reuveni I, Barkai E, Lamprecht R. Learning-induced enduring changes in inhibitory synaptic transmission in lateral amygdala are mediated by p21-activated kinase. J Neurophysiol 2020; 123:178-190. [DOI: 10.1152/jn.00559.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In this study we explored whether learning leads to enduring changes in inhibitory synaptic transmission in lateral amygdala (LA). We revealed that olfactory discrimination (OD) learning in rats led to a long-lasting increase in postsynaptic GABAA channel-mediated miniature inhibitory postsynaptic currents (mIPSCs) in LA. Olfactory fear conditioning, but not auditory fear conditioning, also led to enduring enhancement in GABAA-mediated mIPSCs. Auditory fear conditioning, but not olfactory fear conditioning or OD learning, induced an enduring reduction in the frequency but not the current of mIPSC events. We found that p21-activated kinase (PAK) activity is needed to maintain OD and olfactory fear conditioning learning-induced enduring enhancement of mIPSCs. Further analysis revealed that OD led to an increase in GABAA channel conductance whereas olfactory fear conditioning increased the number of GABAA channels. These alterations in GABAA channels conductance and level are controlled by PAK activity. Our study shows that the learning-induced increase in postsynaptic inhibitory transmission in LA is specific to the sensory modality. However, the mechanism that mediates the increase in inhibitory transmission, namely the increase in the conductance or in the level of GABAA channel, is learning specific. NEW & NOTEWORTHY Here we studied whether learning leads to long-lasting alterations in inhibitory synaptic transmission in lateral amygdala (LA). We revealed that learning led to enduring changes in inhibitory synaptic transmission in LA that are affected by the sensory modality (auditory or olfaction) used during learning. However, the mechanism that mediated the changes in inhibitory transmission (alterations in GABAA channel level or conductance) depended on the type of learning. These long-lasting alterations are maintained by p21-activated kinase.
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Affiliation(s)
- Blesson K. Paul
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Iris Reuveni
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Edi Barkai
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Raphael Lamprecht
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
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15
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Diering GH, Huganir RL. The AMPA Receptor Code of Synaptic Plasticity. Neuron 2019; 100:314-329. [PMID: 30359599 DOI: 10.1016/j.neuron.2018.10.018] [Citation(s) in RCA: 510] [Impact Index Per Article: 102.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 01/02/2023]
Abstract
Changes in the properties and postsynaptic abundance of AMPA-type glutamate receptors (AMPARs) are major mechanisms underlying various forms of synaptic plasticity, including long-term potentiation (LTP), long-term depression (LTD), and homeostatic scaling. The function and the trafficking of AMPARs to and from synapses is modulated by specific AMPAR GluA1-GluA4 subunits, subunit-specific protein interactors, auxiliary subunits, and posttranslational modifications. Layers of regulation are added to AMPAR tetramers through these different interactions and modifications, increasing the computational power of synapses. Here we review the reliance of synaptic plasticity on AMPAR variants and propose "the AMPAR code" as a conceptual framework. The AMPAR code suggests that AMPAR variants will be predictive of the types and extent of synaptic plasticity that can occur and that a hierarchy exists such that certain AMPARs will be disproportionally recruited to synapses during LTP/homeostatic scaling up, or removed during LTD/homeostatic scaling down.
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Affiliation(s)
- Graham H Diering
- Department of Cell Biology and Physiology, and Neuroscience Center, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Richard L Huganir
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA.
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16
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Friedrich SR, Lovell PV, Kaser TM, Mello CV. Exploring the molecular basis of neuronal excitability in a vocal learner. BMC Genomics 2019; 20:629. [PMID: 31375088 PMCID: PMC6679542 DOI: 10.1186/s12864-019-5871-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/31/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Vocal learning, the ability to learn to produce vocalizations through imitation, relies on specialized brain circuitry known in songbirds as the song system. While the connectivity and various physiological properties of this system have been characterized, the molecular genetic basis of neuronal excitability in song nuclei remains understudied. We have focused our efforts on examining voltage-gated ion channels to gain insight into electrophysiological and functional features of vocal nuclei. A previous investigation of potassium channel genes in zebra finches (Taeniopygia guttata) revealed evolutionary modifications unique to songbirds, as well as transcriptional specializations in the song system [Lovell PV, Carleton JB, Mello CV. BMC Genomics 14:470 2013]. Here, we expand this approach to sodium, calcium, and chloride channels along with their modulatory subunits using comparative genomics and gene expression analysis encompassing microarrays and in situ hybridization. RESULTS We found 23 sodium, 38 calcium, and 33 chloride channel genes (HGNC-based classification) in the zebra finch genome, several of which were previously unannotated. We determined 15 genes are missing relative to mammals, including several genes (CLCAs, BEST2) linked to olfactory transduction. The majority of sodium and calcium but few chloride channels showed differential expression in the song system, among them SCN8A and CACNA1E in the direct motor pathway, and CACNG4 and RYR2 in the anterior forebrain pathway. In several cases, we noted a seemingly coordinated pattern across multiple nuclei (SCN1B, SCN3B, SCN4B, CACNB4) or sparse expression (SCN1A, CACNG5, CACNA1B). CONCLUSION The gene families examined are highly conserved between avian and mammalian lineages. Several cases of differential expression likely support high-frequency and burst firing in specific song nuclei, whereas cases of sparse patterns of expression may contribute to the unique electrophysiological signatures of distinct cell populations. These observations lay the groundwork for manipulations to determine how ion channels contribute to the neuronal excitability properties of vocal learning systems.
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Affiliation(s)
- Samantha R. Friedrich
- Department of Behavioral Neuroscience, Oregon Health and Science University, 3181 Sam Jackson Park Rd L470, Portland, OR USA
| | - Peter V. Lovell
- Department of Behavioral Neuroscience, Oregon Health and Science University, 3181 Sam Jackson Park Rd L470, Portland, OR USA
| | - Taylor M. Kaser
- Department of Behavioral Neuroscience, Oregon Health and Science University, 3181 Sam Jackson Park Rd L470, Portland, OR USA
| | - Claudio V. Mello
- Department of Behavioral Neuroscience, Oregon Health and Science University, 3181 Sam Jackson Park Rd L470, Portland, OR USA
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17
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Bissen D, Foss F, Acker-Palmer A. AMPA receptors and their minions: auxiliary proteins in AMPA receptor trafficking. Cell Mol Life Sci 2019; 76:2133-2169. [PMID: 30937469 PMCID: PMC6502786 DOI: 10.1007/s00018-019-03068-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/12/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022]
Abstract
To correctly transfer information, neuronal networks need to continuously adjust their synaptic strength to extrinsic stimuli. This ability, termed synaptic plasticity, is at the heart of their function and is, thus, tightly regulated. In glutamatergic neurons, synaptic strength is controlled by the number and function of AMPA receptors at the postsynapse, which mediate most of the fast excitatory transmission in the central nervous system. Their trafficking to, at, and from the synapse, is, therefore, a key mechanism underlying synaptic plasticity. Intensive research over the last 20 years has revealed the increasing importance of interacting proteins, which accompany AMPA receptors throughout their lifetime and help to refine the temporal and spatial modulation of their trafficking and function. In this review, we discuss the current knowledge about the roles of key partners in regulating AMPA receptor trafficking and focus especially on the movement between the intracellular, extrasynaptic, and synaptic pools. We examine their involvement not only in basal synaptic function, but also in Hebbian and homeostatic plasticity. Included in our review are well-established AMPA receptor interactants such as GRIP1 and PICK1, the classical auxiliary subunits TARP and CNIH, and the newest additions to AMPA receptor native complexes.
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Affiliation(s)
- Diane Bissen
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany
| | - Franziska Foss
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany.
- Cardio-Pulmonary Institute (CPI), Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
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18
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Radin DP, Li YX, Rogers G, Purcell R, Lippa A. Tarps differentially affect the pharmacology of ampakines. Biochem Pharmacol 2018; 154:446-451. [PMID: 29906466 DOI: 10.1016/j.bcp.2018.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/11/2018] [Indexed: 12/29/2022]
Abstract
Transmembrane AMPA receptor regulatory proteins (TARPs) govern AMPA receptor cell surface expression and distinct physiological properties including agonist affinity, desensitization and deactivation kinetics. The prototypical TARP, STG or γ2 and TARPs γ3, γ4, γ7 and γ8 are all expressed to varying degrees in the mammalian brain and differentially regulate AMPAR gating parameters. Positive allosteric AMPA receptor modulators or ampakines alter receptor rates of agonist binding/unbinding, channel opening and can offset receptor desensitization and deactivation. The effects of the two ampakines, CX614 and cyclothiazide (CTZ) were evaluated on homomeric GluR1-flip receptors and GluR2-flop receptors expressed on HEK293 cells by transient transfection with or without different TARPs γ2, γ3, γ4 or γ8 genes. γ4 was the most robust TARP in increasing the affinities of CX614 and CTZ on GluR1-flip receptors, but had no such effect on GluR2-flop receptors. However, γ8 gave the most significant increases in affinities of CX614 and CTZ on GluR2-flop. These data show that TARPs differentially affect the surface expression and kinetics of the AMPA receptor, as well as the pharmacology of ampakines for the AMPA receptor. The modulatory effects of TARPs on ampakine pharmacology are complex, being dependent on both the TARP subtype and the AMPA receptor subtypes/isoforms.
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Affiliation(s)
- Daniel P Radin
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States.
| | - Yong-Xin Li
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
| | - Gary Rogers
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
| | - Richard Purcell
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
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19
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Complex-learning Induced Modifications in Synaptic Inhibition: Mechanisms and Functional Significance. Neuroscience 2018; 381:105-114. [DOI: 10.1016/j.neuroscience.2018.04.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 12/17/2022]
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20
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Zhou J, Benito-Martin A, Mighty J, Chang L, Ghoroghi S, Wu H, Wong M, Guariglia S, Baranov P, Young M, Gharbaran R, Emerson M, Mark MT, Molina H, Canto-Soler MV, Selgas HP, Redenti S. Retinal progenitor cells release extracellular vesicles containing developmental transcription factors, microRNA and membrane proteins. Sci Rep 2018; 8:2823. [PMID: 29434302 PMCID: PMC5809580 DOI: 10.1038/s41598-018-20421-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 01/15/2018] [Indexed: 12/27/2022] Open
Abstract
A range of cell types, including embryonic stem cells, neurons and astrocytes have been shown to release extracellular vesicles (EVs) containing molecular cargo. Across cell types, EVs facilitate transfer of mRNA, microRNA and proteins between cells. Here we describe the release kinetics and content of EVs from mouse retinal progenitor cells (mRPCs). Interestingly, mRPC derived EVs contain mRNA, miRNA and proteins associated with multipotency and retinal development. Transcripts enclosed in mRPC EVs, include the transcription factors Pax6, Hes1, and Sox2, a mitotic chromosome stabilizer Ki67, and the neural intermediate filaments Nestin and GFAP. Proteomic analysis of EV content revealed retinogenic growth factors and morphogen proteins. mRPC EVs were shown to transfer GFP mRNA between cell populations. Finally, analysis of EV mediated functional cargo delivery, using the Cre-loxP recombination system, revealed transfer and uptake of Cre+ EVs, which were then internalized by target mRPCs activating responder loxP GFP expression. In summary, the data supports a paradigm of EV genetic material encapsulation and transfer within RPC populations. RPC EV transfer may influence recipient RPC transcriptional and post-transcriptional regulation, representing a novel mechanism of differentiation and fate determination during retinal development.
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Affiliation(s)
- Jing Zhou
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA.,Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Alberto Benito-Martin
- Children's Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children's Health, Meyer Cancer Center, Weill Cornell Medical College, New York, New York, 10021, USA
| | - Jason Mighty
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA.,Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Lynne Chang
- Nikon Instruments Inc, 1300 Walt Whitman Road, Melville, NY, 11747, USA
| | - Shima Ghoroghi
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | - Hao Wu
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA.,Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Madeline Wong
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | - Sara Guariglia
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 722 West 168th St, New York, NY, 10032, USA
| | - Petr Baranov
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA, 02114, USA
| | - Michael Young
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA, 02114, USA
| | - Rajendra Gharbaran
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | - Mark Emerson
- Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA.,Department of Biology, The City College of New York, City University of New York, New York, NY, 10031, USA
| | - Milica Tesic Mark
- Proteomics Resource Center, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - M Valeria Canto-Soler
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Hector Peinado Selgas
- Children's Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children's Health, Meyer Cancer Center, Weill Cornell Medical College, New York, New York, 10021, USA.,Microenvironment and Metastasis Laboratory, Department of Molecular Oncology, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro, 3, Madrid, E28029, Spain
| | - Stephen Redenti
- Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA. .,Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA. .,Biochemistry Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA.
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21
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Lee MR, Gardinier KM, Gernert DL, Schober DA, Wright RA, Wang H, Qian Y, Witkin JM, Nisenbaum ES, Kato AS. Structural Determinants of the γ-8 TARP Dependent AMPA Receptor Antagonist. ACS Chem Neurosci 2017; 8:2631-2647. [PMID: 28825787 DOI: 10.1021/acschemneuro.7b00186] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The forebrain specific AMPA receptor antagonist, LY3130481/CERC-611, which selectively antagonizes the AMPA receptors associated with TARP γ-8, an auxiliary subunit enriched in the forebrain, has potent antiepileptic activities without motor side effects. We designated the compounds with such activities as γ-8 TARP dependent AMPA receptor antagonists (γ-8 TDAAs). In this work, we further investigated the mechanisms of action using a radiolabeled γ-8 TDAA and ternary structural modeling with mutational validations to characterize the LY3130481 binding to γ-8. The radioligand binding to the cells heterologously expressing GluA1 and/or γ-8 revealed that γ-8 TDAAs binds to γ-8 alone without AMPA receptors. Homology modeling of γ-8, based on the crystal structures of a distant TARP homologue, murine claudin 19, in conjunction with knowledge of two γ-8 residues previously identified as critical for the LY3130481 TARP-dependent selectivity provided the basis for a binding mode prediction. This allowed further rational mutational studies for characterization of the structural determinants in TARP γ-8 for LY3130481 activities, both thermodynamically as well as kinetically.
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Affiliation(s)
- Matthew R. Lee
- Lilly
Biotechnology Center, Eli Lilly and Company, 10300 Campus Point Dr. #200, San Diego, California 92121, United States
| | - Kevin M. Gardinier
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Douglas L. Gernert
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Douglas A. Schober
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Rebecca A. Wright
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - He Wang
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Yuewei Qian
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Jeffrey M. Witkin
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Eric S. Nisenbaum
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Akihiko S. Kato
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
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Kato AS, Witkin JM. Auxiliary subunits of AMPA receptors: The discovery of a forebrain-selective antagonist, LY3130481/CERC-611. Biochem Pharmacol 2017; 147:191-200. [PMID: 28987594 DOI: 10.1016/j.bcp.2017.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/27/2017] [Indexed: 12/11/2022]
Abstract
Drugs originate from the discovery of compounds, natural or synthetic, that bind to proteins (receptors, enzymes, transporters, etc.), the interaction of which modulates biological cascades that have potential therapeutic benefit. Rational strategies for identifying novel drug therapies are typically based on knowledge of the structure of the target proteins and the design of new chemical entities that modulate these proteins in a beneficial manner. The present review discusses a novel approach to drug discovery based on the identification and characterization of auxiliary proteins, the transmembrane AMPA receptor regulatory proteins (TARPs) that are associated with AMPA receptors. Utilizing these auxiliary proteins in compound screening led to the discovery of the TARP-dependent-AMPA forebrain selective receptor antagonist (TDAA), LY3130481/CERC-611 that is currently in clinical development for epilepsy.
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Affiliation(s)
- Akihiko S Kato
- Neuroscience Discovery Research, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN 46285-0510, United States.
| | - Jeffrey M Witkin
- Neuroscience Discovery Research, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN 46285-0510, United States.
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23
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Woller SA, Eddinger KA, Corr M, Yaksh TL. An overview of pathways encoding nociception. Clin Exp Rheumatol 2017; 35 Suppl 107:40-46. [PMID: 28967373 PMCID: PMC6636838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 06/07/2023]
Abstract
The nervous system detects and interprets a variety of chemical, mechanical, and thermal stimuli. In the face of tissue injury, local inflammatory products perpetuate ongoing activity and sensitisation of the peripheral nerve termini. This ongoing activity evokes a state of robust spinal facilitation mediated by a number of local circuits, the net effect yielding an enhanced message of nociception to higher centres. This messaging typically wanes with the resolution of inflammation or wound healing. However, there are situations in which peripheral and central components of the pain transmission pathway extend and enhance the pain state, leading to a persistent hypersensitivity, e.g., an acute to chronic pain transition. Current work points to the contribution of innate and adaptive immunity in creating these enduring conditions. We briefly describe the underlying biological components of both physiological pain processing and pathological pain processing, as well as the acute to chronic pain transition and the role of innate and adaptive immunity in this transition.
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Affiliation(s)
- Sarah A Woller
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Kelly A Eddinger
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Maripat Corr
- Division of Rheumatology, Allergy, and Immunology, University of California San Diego, La Jolla, CA, USA
| | - Tony L Yaksh
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA.
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24
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TARP γ-2 Is Required for Inflammation-Associated AMPA Receptor Plasticity within Lamina II of the Spinal Cord Dorsal Horn. J Neurosci 2017; 37:6007-6020. [PMID: 28559374 PMCID: PMC5481940 DOI: 10.1523/jneurosci.0772-16.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 03/30/2017] [Accepted: 04/12/2017] [Indexed: 12/21/2022] Open
Abstract
In the brain, transmembrane AMPAR regulatory proteins (TARPs) critically influence the distribution, gating, and pharmacology of AMPARs, but the contribution of these auxiliary subunits to AMPAR-mediated signaling in the spinal cord remains unclear. We found that the Type I TARP γ-2 (stargazin) is present in lamina II of the superficial dorsal horn, an area involved in nociception. Consistent with the notion that γ-2 is associated with surface AMPARs, CNQX, a partial agonist at AMPARs associated with Type I TARPs, evoked whole-cell currents in lamina II neurons, but such currents were severely attenuated in γ-2-lacking stargazer (stg/stg) mice. Examination of EPSCs revealed the targeting of γ-2 to be synapse-specific; the amplitude of spontaneously occurring miniature EPSCs (mEPSCs) was reduced in neurons from stg/stg mice, but the amplitude of capsaicin-induced mEPSCs from C-fiber synapses was unaltered. This suggests that γ-2 is associated with AMPARs at synapses in lamina II but excluded from those at C-fiber inputs, a view supported by our immunohistochemical colabeling data. Following induction of peripheral inflammation, a model of hyperalgesia, there was a switch in the current-voltage relationships of capsaicin-induced mEPSCs, from linear to inwardly rectifying, indicating an increased prevalence of calcium-permeable (CP) AMPARs. This effect was abolished in stg/stg mice. Our results establish that, although γ-2 is not typically associated with calcium-impermeable AMPARs at C-fiber synapses, it is required for the translocation of CP-AMPARs to these synapses following peripheral inflammation.SIGNIFICANCE STATEMENT In the brain, transmembrane AMPAR regulatory proteins (TARPs) critically determine the functional properties of AMPARs, but the contribution of these auxiliary subunits to AMPAR-mediated signaling in the spinal cord remains unclear. An increase in the excitability of neurons within the superficial dorsal horn (SDH) of the spinal cord is thought to underlie heighted pain sensitivity. One mechanism considered to contribute to such long-lived changes is the remodeling of the ionotropic AMPA-type glutamate receptors that underlie fast excitatory synaptic transmission in the SDH. Here we show that the TARP γ-2 (stargazin) is present in SDH neurons and is necessary in a form of inflammatory pain-induced plasticity, which involves an increase in the prevalence of synaptic calcium-permeable AMPARs.
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Greger IH, Watson JF, Cull-Candy SG. Structural and Functional Architecture of AMPA-Type Glutamate Receptors and Their Auxiliary Proteins. Neuron 2017; 94:713-730. [DOI: 10.1016/j.neuron.2017.04.009] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/04/2017] [Accepted: 04/05/2017] [Indexed: 12/20/2022]
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26
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Lee MY, Ha SE, Park C, Park PJ, Fuchs R, Wei L, Jorgensen BG, Redelman D, Ward SM, Sanders KM, Ro S. Transcriptome of interstitial cells of Cajal reveals unique and selective gene signatures. PLoS One 2017; 12:e0176031. [PMID: 28426719 PMCID: PMC5398589 DOI: 10.1371/journal.pone.0176031] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 04/04/2017] [Indexed: 01/18/2023] Open
Abstract
Transcriptome-scale data can reveal essential clues into understanding the underlying molecular mechanisms behind specific cellular functions and biological processes. Transcriptomics is a continually growing field of research utilized in biomarker discovery. The transcriptomic profile of interstitial cells of Cajal (ICC), which serve as slow-wave electrical pacemakers for gastrointestinal (GI) smooth muscle, has yet to be uncovered. Using copGFP-labeled ICC mice and flow cytometry, we isolated ICC populations from the murine small intestine and colon and obtained their transcriptomes. In analyzing the transcriptome, we identified a unique set of ICC-restricted markers including transcription factors, epigenetic enzymes/regulators, growth factors, receptors, protein kinases/phosphatases, and ion channels/transporters. This analysis provides new and unique insights into the cellular and biological functions of ICC in GI physiology. Additionally, we constructed an interactive ICC genome browser (http://med.unr.edu/physio/transcriptome) based on the UCSC genome database. To our knowledge, this is the first online resource that provides a comprehensive library of all known genetic transcripts expressed in primary ICC. Our genome browser offers a new perspective into the alternative expression of genes in ICC and provides a valuable reference for future functional studies.
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Affiliation(s)
- Moon Young Lee
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
- Department of Physiology, Wonkwang Digestive Disease Research Institute and Institute of Wonkwang Medical Science, School of Medicine, Wonkwang University, Iksan, Jeollabuk-do, Korea
| | - Se Eun Ha
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Chanjae Park
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Paul J. Park
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Robert Fuchs
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Lai Wei
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Brian G. Jorgensen
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Doug Redelman
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Sean M. Ward
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Seungil Ro
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
- * E-mail:
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27
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Mao X, Gu X, Lu W. GSG1L regulates the strength of AMPA receptor-mediated synaptic transmission but not AMPA receptor kinetics in hippocampal dentate granule neurons. J Neurophysiol 2016; 117:28-35. [PMID: 27707810 DOI: 10.1152/jn.00307.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 10/03/2016] [Indexed: 11/22/2022] Open
Abstract
GSG1L is an AMPA receptor (AMPAR) auxiliary subunit that regulates AMPAR trafficking and function in hippocampal CA1 pyramidal neurons. However, its physiological roles in other types of neurons remain to be characterized. Here, we investigated the role of GSG1L in hippocampal dentate granule cells and found that GSG1L is important for the regulation of synaptic strength but is not critical for the modulation of AMPAR deactivation and desensitization kinetics. These data demonstrate a neuronal type-specific role of GSG1L and suggest that physiological function of AMPAR auxiliary subunits may vary in different types of neurons. NEW & NOTEWORTHY GSG1L is a newly identified AMPA receptor (AMPAR) auxiliary subunit and plays a unique role in the regulation of AMPAR trafficking and function in hippocampal CA1 pyramidal neurons. However, its role in the regulation of AMPARs in hippocampal dentate granule cells remains to be characterized. The current work reveals that GSG1L regulates strength of AMPAR-mediated synaptic transmission but not the receptor kinetic properties in hippocampal dentate granule neurons.
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Affiliation(s)
- Xia Mao
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Xinglong Gu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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28
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Zelena D, Mikics É, Balázsfi D, Varga J, Klausz B, Urbán E, Sipos E, Biró L, Miskolczi C, Kovács K, Ferenczi S, Haller J. Enduring abolishment of remote but not recent expression of conditioned fear by the blockade of calcium-permeable AMPA receptors before extinction training. Psychopharmacology (Berl) 2016; 233:2065-2076. [PMID: 27020785 DOI: 10.1007/s00213-016-4255-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 02/21/2016] [Indexed: 11/29/2022]
Abstract
RATIONALE Calcium-permeable (GluA2 subunit-free) AMPA receptors (CP-AMPAR) play prominent roles in fear extinction; however, no blockers of these receptors were studied in tests relevant to extinction learning so far. METHODS The CP-AMPAR antagonist IEM-1460 was administered once before extinction trainings, which were started either 1 or 28 days after fear conditioning (FC). We used a mild extinction protocol that durably decreased but did not abolish conditioned fear. The messenger RNA (mRNA) expression of GluA1 and GluA2 subunits were investigated at both time points in the ventromedial prefrontal cortex (vmPFC) and amygdala. RESULTS IEM-1460 transiently facilitated extinction 1 day after conditioning, but learned fear spontaneously recovered 4 weeks later. When the extinction protocol was applied 28 days after training, IEM-1460 enhanced extinction memory, moreover abolished conditioned fear for at least a month. The expression of GluA1 and GluA2 mRNAs was increased at both time points in the vmPFC. In the basolateral and central amygdala, the GluA1/GluA2 mRNA ratio increased, suggesting a shift towards the preponderance of GluA1 over GluA2 expression. CONCLUSIONS AMPAR blockade lastingly enhanced the extinction of remote but not recent fear memories. Time-dependent changes in AMPA receptor subunit mRNA expression may explain the differential effects of CP-AMPAR blockade on recent and remote conditioned fear, further supporting the notion that the mechanisms maintaining learned fear change over time. Our findings suggest clinical implications for CP-AMPAR blockers, particularly for acquired anxieties (e.g., post-traumatic stress disorder) which have a slow onset and are durable.
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Affiliation(s)
- Dóra Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary.
| | - Éva Mikics
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - Diána Balázsfi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - János Varga
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - Barbara Klausz
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - Eszter Urbán
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - Eszter Sipos
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - László Biró
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Christina Miskolczi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - Krisztina Kovács
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - Szilamér Ferenczi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - József Haller
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
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Abstract
AMPA receptors (AMPARs) are assemblies of four core subunits, GluA1-4, that mediate most fast excitatory neurotransmission. The component subunits determine the functional properties of AMPARs, and the prevailing view is that the subunit composition also determines AMPAR trafficking, which is dynamically regulated during development, synaptic plasticity and in response to neuronal stress in disease. Recently, the subunit dependence of AMPAR trafficking has been questioned, leading to a reappraisal of this field. In this Review, we discuss what is known, uncertain, conjectured and unknown about the roles of the individual subunits, and how they affect AMPAR assembly, trafficking and function under both normal and pathological conditions.
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30
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Gu X, Mao X, Lussier MP, Hutchison MA, Zhou L, Hamra FK, Roche KW, Lu W. GSG1L suppresses AMPA receptor-mediated synaptic transmission and uniquely modulates AMPA receptor kinetics in hippocampal neurons. Nat Commun 2016; 7:10873. [PMID: 26932439 PMCID: PMC4778064 DOI: 10.1038/ncomms10873] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 01/28/2016] [Indexed: 12/17/2022] Open
Abstract
Regulation of AMPA receptor (AMPAR)-mediated synaptic transmission is a key mechanism
for synaptic plasticity. In the brain, AMPARs assemble with a number of auxiliary
subunits, including TARPs, CNIHs and CKAMP44, which are important for AMPAR forward
trafficking to synapses. Here we report that the membrane protein GSG1L negatively
regulates AMPAR-mediated synaptic transmission. Overexpression of GSG1L strongly
suppresses, and GSG1L knockout (KO) enhances, AMPAR-mediated synaptic transmission.
GSG1L-dependent regulation of AMPAR synaptic transmission relies on the first
extracellular loop domain and its carboxyl-terminus. GSG1L also speeds up AMPAR
deactivation and desensitization in hippocampal CA1 neurons, in contrast to the
effects of TARPs and CNIHs. Furthermore, GSG1L association with AMPARs inhibits
CNIH2-induced slowing of the receptors in heterologous cells. Finally, GSG1L KO rats
have deficits in LTP and show behavioural abnormalities in object recognition tests.
These data demonstrate that GSG1L represents a new class of auxiliary subunit with
distinct functional properties for AMPARs. The molecular mechanism controlling the trafficking and function of
AMPARs at synapses are not fully understood. Here the authors show that GSG1L, a
membrane protein, negatively regulates AMPAR-mediated synaptic transmission and
represents a new class of AMPAR auxiliary subunit.
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Affiliation(s)
- Xinglong Gu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 3C1000, Bethesda, Maryland 20892, USA
| | - Xia Mao
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 3C1000, Bethesda, Maryland 20892, USA
| | - Marc P Lussier
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 2C903, Bethesda, Maryland 20892, USA
| | - Mary Anne Hutchison
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 3C1000, Bethesda, Maryland 20892, USA
| | - Liang Zhou
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 3C1000, Bethesda, Maryland 20892, USA
| | - F Kent Hamra
- Department of Pharmacology, Cecil H. &Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center in Dallas, Dallas, Texas 75390, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 2C903, Bethesda, Maryland 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, 3C1000, Bethesda, Maryland 20892, USA
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31
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Superactivation of AMPA receptors by auxiliary proteins. Nat Commun 2016; 7:10178. [PMID: 26744192 PMCID: PMC4729862 DOI: 10.1038/ncomms10178] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/11/2015] [Indexed: 12/15/2022] Open
Abstract
Glutamate receptors form complexes in the brain with auxiliary proteins, which control their activity during fast synaptic transmission through a seemingly bewildering array of effects. Here we devise a way to isolate the activation of complexes using polyamines, which enables us to show that transmembrane AMPA receptor regulatory proteins (TARPs) exert their effects principally on the channel opening reaction. A thermodynamic argument suggests that because TARPs promote channel opening, receptor activation promotes AMPAR-TARP complexes into a superactive state with high open probability. A simple model based on this idea predicts all known effects of TARPs on AMPA receptor function. This model also predicts unexpected phenomena including massive potentiation in the absence of desensitization and supramaximal recovery that we subsequently detected in electrophysiological recordings. This transient positive feedback mechanism has implications for information processing in the brain, because it should allow activity-dependent facilitation of excitatory synaptic transmission through a postsynaptic mechanism. Transmembrane AMPA receptor regulatory proteins (TARPs) exert a number of effects on fast glutamatergic synaptic transmission. Here, the authors model the interactions of two such proteins, Stargazin and γ-8, and propose a simple kinetic mechanism by which TARPs modulate channel opening reaction.
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32
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Lalanne T, Oyrer J, Mancino A, Gregor E, Chung A, Huynh L, Burwell S, Maheux J, Farrant M, Sjöström PJ. Synapse-specific expression of calcium-permeable AMPA receptors in neocortical layer 5. J Physiol 2015; 594:837-61. [PMID: 26537662 PMCID: PMC4753277 DOI: 10.1113/jp271394] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/01/2015] [Indexed: 01/26/2023] Open
Abstract
Key points In the hippocampus, calcium‐permeable AMPA receptors have been found in a restricted subset of neuronal types that inhibit other neurons, although their localization in the neocortex is less well understood. In the present study, we looked for calcium‐permeable AMPA receptors in two distinct populations of neocortical inhibitory neurons: basket cells and Martinotti cells. We found them in the former but not in the latter. Furthermore, in basket cells, these receptors were associated with particularly fast responses. Computer modelling predicted (and experiments verified) that fast calcium‐permeable AMPA receptors enable basket cells to respond rapidly, such that they promptly inhibit neighbouring cells and shut down activity. The results obtained in the present study help our understanding of pathologies such as stroke and epilepsy that have been associated with disordered regulation of calcium‐permeable AMPA receptors.
Abstract AMPA‐type glutamate receptors (AMPARs) lacking an edited GluA2 subunit are calcium‐permeable (CP) and contribute to synaptic plasticity in several hippocampal interneuron types, although their precise role in the neocortex is not well described. We explored the presence of CP‐AMPARs at pyramidal cell (PC) inputs to Martinotti cells (MCs) and basket cells (BCs) in layer 5 of the developing mouse visual cortex (postnatal days 12–21). GluA2 immunolabelling was stronger in MCs than in BCs. A differential presence of CP‐AMPARs at PC‐BC and PC‐MC synapses was confirmed electrophysiologically, based on measures of spermine‐dependent rectification and CP‐AMPAR blockade by 1‐naphtyl acetyl spermine using recordings from synaptically connected cell pairs, NPEC‐AMPA uncaging and miniature current recordings. In addition, CP‐AMPAR expression in BCs was correlated with rapidly decaying synaptic currents. Computer modelling predicted that this reduces spike latencies and sharpens suprathreshold responses in BCs, which we verified experimentally using the dynamic clamp technique. Thus, the synapse‐specific expression of CP‐AMPARs may critically influence both plasticity and information processing in neocortical microcircuits. In the hippocampus, calcium‐permeable AMPA receptors have been found in a restricted subset of neuronal types that inhibit other neurons, although their localization in the neocortex is less well understood. In the present study, we looked for calcium‐permeable AMPA receptors in two distinct populations of neocortical inhibitory neurons: basket cells and Martinotti cells. We found them in the former but not in the latter. Furthermore, in basket cells, these receptors were associated with particularly fast responses. Computer modelling predicted (and experiments verified) that fast calcium‐permeable AMPA receptors enable basket cells to respond rapidly, such that they promptly inhibit neighbouring cells and shut down activity. The results obtained in the present study help our understanding of pathologies such as stroke and epilepsy that have been associated with disordered regulation of calcium‐permeable AMPA receptors.
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Affiliation(s)
- Txomin Lalanne
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Julia Oyrer
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Adamo Mancino
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Erica Gregor
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Andrew Chung
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Louis Huynh
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Sasha Burwell
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Jérôme Maheux
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada.,Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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Roy B, Ahmed KT, Cunningham ME, Ferdous J, Mukherjee R, Zheng W, Chen XZ, Ali DW. Zebrafish TARP Cacng2 is required for the expression and normal development of AMPA receptors at excitatory synapses. Dev Neurobiol 2015; 76:487-506. [PMID: 26178704 DOI: 10.1002/dneu.22327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 07/01/2015] [Accepted: 07/14/2015] [Indexed: 01/03/2023]
Abstract
Fast excitatory synaptic transmission in the CNS is mediated by the neurotransmitter glutamate, binding to and activating AMPA receptors (AMPARs). AMPARs are known to interact with auxiliary proteins that modulate their behavior. One such family of proteins is the transmembrane AMPA receptor-related proteins, known as TARPs. Little is known about the role of TARPs during development, or about their function in non-mammalian organisms. Here we report the presence of TARPs, specifically the prototypical TARP, stargazin, in developing zebrafish. We find that zebrafish express two forms of stargazin, Cacng2a and Cacng2b from as early as 12-h post fertilization (hpf). Knockdown of Cacng2a and Cacng2b via splice-blocking morpholinos resulted in embryos that exhibited deficits in C-start escape responses, showing reduced C-bend angles, smaller tail velocities and aberrant C-bend turning directions. Injection of the morphants with Cacng2a or 2b mRNA rescued the morphological phenotype and the synaptic deficits. To investigate the effect of reduced Cacng2a and 2b levels on synaptic physiology, we performed whole cell patch clamp recordings of AMPA mEPSCs from zebrafish Mauthner cells. Knockdown of Cacng2a results in reduced AMPA currents and lower mEPSC frequencies, whereas knockdown of Cacng2b displayed no significant change in mEPSC amplitude or frequency. Non-stationary fluctuation analysis confirmed a reduction in the number of active synaptic receptors in the Cacng2a but not in the Cacng2b morphants. Together, these results suggest that Cacng2a is required for normal trafficking and function of synaptic AMPARs, while Cacng2b is largely non-functional with respect to the development of AMPA synaptic transmission.
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Affiliation(s)
- Birbickram Roy
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Kazi T Ahmed
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Marcus E Cunningham
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Jannatul Ferdous
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Rajarshi Mukherjee
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Wang Zheng
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| | - Xing-Zhen Chen
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| | - Declan W Ali
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9.,Department of Physiology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7.,Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada, T6G 2E1
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Yaksh TL, Woller SA, Ramachandran R, Sorkin LS. The search for novel analgesics: targets and mechanisms. F1000PRIME REPORTS 2015; 7:56. [PMID: 26097729 PMCID: PMC4447049 DOI: 10.12703/p7-56] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The management of the pain state is of great therapeutic relevance to virtually every medical specialty. Failure to manage its expression has deleterious consequence to the well-being of the organism. An understanding of the complex biology of the mechanisms underlying the processing of nociceptive information provides an important pathway towards development of novel and robust therapeutics. Importantly, preclinical models have been of considerable use in determining the linkage between mechanism and the associated behaviorally defined pain state. This review seeks to provide an overview of current thinking targeting pain biology, the use of preclinical models and the development of novel pain therapeutics. Issues pertinent to the strengths and weaknesses of current development strategies for analgesics are considered.
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Transmembrane AMPAR regulatory protein γ-2 is required for the modulation of GABA release by presynaptic AMPARs. J Neurosci 2015; 35:4203-14. [PMID: 25762667 DOI: 10.1523/jneurosci.4075-14.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Presynaptic ionotropic glutamate receptors (iGluRs) play important roles in the control of synaptogenesis and neurotransmitter release, yet their regulation is poorly understood. In particular, the contribution of transmembrane auxiliary proteins, which profoundly shape the trafficking and gating of somatodendritic iGluRs, is unknown. Here we examined the influence of transmembrane AMPAR regulatory proteins (TARPs) on presynaptic AMPARs in cerebellar molecular layer interneurons (MLIs). 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), a partial agonist at TARP-associated AMPARs, enhanced spontaneous GABA release in wild-type mice but not in stargazer mice that lack the prototypical TARP stargazin (γ-2). These findings were replicated in mechanically dissociated Purkinje cells with functional adherent synaptic boutons, demonstrating the presynaptic locus of modulation. In dissociated Purkinje cells from stargazer mice, AMPA was able to enhance mIPSC frequency, but only in the presence of the positive allosteric modulator cyclothiazide. Thus, ordinarily, presynaptic AMPARs are unable to enhance spontaneous release without γ-2, which is required predominantly for its effects on channel gating. Presynaptic AMPARs are known to reduce action potential-driven GABA release from MLIs. Although a G-protein-dependent non-ionotropic mechanism has been suggested to underlie this inhibition, paradoxically we found that γ-2, and thus AMPAR gating, was required. Following glutamate spillover from climbing fibers or application of CNQX, evoked GABA release was reduced; in stargazer mice such effects were markedly attenuated in acute slices and abolished in the dissociated Purkinje cell-nerve bouton preparation. We suggest that γ-2 association, by increasing charge transfer, allows presynaptic AMPARs to depolarize the bouton membrane sufficiently to modulate both phasic and spontaneous release.
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Persistent CaMKII activation mediates learning-induced long-lasting enhancement of synaptic inhibition. J Neurosci 2015; 35:128-39. [PMID: 25568108 DOI: 10.1523/jneurosci.2123-14.2015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Training rats in a particularly difficult olfactory-discrimination task results in acquisition of high skill to perform the task superbly, termed "rule learning" or "learning set." Such complex learning results in enhanced intrinsic neuronal excitability of piriform cortex pyramidal neurons, and in their excitatory synaptic interconnections. These changes, while subserving memory maintenance, must be counterbalanced by modifications that prevent overspreading of activity and uncontrolled synaptic strengthening. Indeed, we have previously shown that the average amplitude of GABAA-mediated miniature IPSCs (mIPSCs) in these neurons is enhanced for several days after learning, an enhancement mediated via a postsynaptic mechanism. To unravel the molecular mechanism of this long-term inhibition enhancement, we tested the role of key second-messenger systems in maintaining such long-lasting modulation. The calcium/calmodulin-dependent kinase II (CaMKII) blocker, KN93, significantly reduced the average mIPSC amplitude in neurons from trained rats only to the average pretraining level. A similar effect was obtained by the CaMKII peptide inhibitor, tatCN21. Such reduction resulted from decreased single-channel conductance and not in the number of activated channels. The PKC inhibitor, GF109203X, reduced the average mIPSC amplitude in neurons from naive, pseudo-trained, and trained animals, and the difference between the trained and control groups remained. Such reduction resulted from a decrease in the number of activated channels. The PKA inhibitor H89 dihydrochloride did not affect the average mIPSC amplitude in neurons from any of the three groups. We conclude that learning-induced enhancement of GABAA-mediated synaptic inhibition is maintained by persistent CaMKII activation.
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Abstract
Voltage- and ligand-gated ion channels form the molecular basis of cellular excitability. With >400 members and accounting for ∼1.5% of the human genome, ion channels are some of the most well studied of all proteins in heterologous expression systems. Yet, ion channels often exhibit unexpected properties in vivo because of their interaction with a variety of signaling/scaffolding proteins. Such interactions can influence the function and localization of ion channels, as well as their coupling to intracellular second messengers and pathways, thus increasing the signaling potential of these ion channels in neurons. Moreover, functions have been ascribed to ion channels that are largely independent of their ion-conducting roles. Molecular and functional dissection of the ion channel proteome/interactome has yielded new insights into the composition of ion channel complexes and how their dysregulation leads to human disease.
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Relative contribution of TARPs γ-2 and γ-7 to cerebellar excitatory synaptic transmission and motor behavior. Proc Natl Acad Sci U S A 2015; 112:E371-9. [PMID: 25583485 DOI: 10.1073/pnas.1423670112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transmembrane AMPA receptor regulatory proteins (TARPs) play an essential role in excitatory synaptic transmission throughout the central nervous system (CNS) and exhibit subtype-specific effects on AMPA receptor (AMPAR) trafficking, gating, and pharmacology. The function of TARPs has largely been determined through work on canonical type I TARPs such as stargazin (TARP γ-2), absent in the ataxic stargazer mouse. Little is known about the function of atypical type II TARPs, such as TARP γ-7, which exhibits variable effects on AMPAR function. Because γ-2 and γ-7 are both strongly expressed in multiple cell types in the cerebellum, we examined the relative contribution of γ-2 and γ-7 to both synaptic transmission in the cerebellum and motor behavior by using both the stargazer mouse and a γ-7 knockout (KO) mouse. We found that the loss of γ-7 alone had little effect on climbing fiber (cf) responses in Purkinje neurons (PCs), yet the additional loss of γ-2 all but abolished cf responses. In contrast, γ-7 failed to make a significant contribution to excitatory transmission in stellate cells and granule cells. In addition, we generated a PC-specific deletion of γ-2, with and without γ-7 KO background, to examine the relative contribution of γ-2 and γ-7 to PC-dependent motor behavior. Selective deletion of γ-2 in PCs had little effect on motor behavior, yet the additional loss of γ-7 resulted in a severe disruption in motor behavior. Thus, γ-7 is capable of supporting a component of excitatory transmission in PCs, sufficient to maintain essentially normal motor behavior, in the absence of γ-2.
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Stepanyuk A, Borisyuk A, Belan P. Maximum likelihood estimation of biophysical parameters of synaptic receptors from macroscopic currents. Front Cell Neurosci 2014; 8:303. [PMID: 25324721 PMCID: PMC4183100 DOI: 10.3389/fncel.2014.00303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/09/2014] [Indexed: 11/13/2022] Open
Abstract
Dendritic integration and neuronal firing patterns strongly depend on biophysical properties of synaptic ligand-gated channels. However, precise estimation of biophysical parameters of these channels in their intrinsic environment is complicated and still unresolved problem. Here we describe a novel method based on a maximum likelihood approach that allows to estimate not only the unitary current of synaptic receptor channels but also their multiple conductance levels, kinetic constants, the number of receptors bound with a neurotransmitter, and the peak open probability from experimentally feasible number of postsynaptic currents. The new method also improves the accuracy of evaluation of unitary current as compared to the peak-scaled non-stationary fluctuation analysis, leading to a possibility to precisely estimate this important parameter from a few postsynaptic currents recorded in steady-state conditions. Estimation of unitary current with this method is robust even if postsynaptic currents are generated by receptors having different kinetic parameters, the case when peak-scaled non-stationary fluctuation analysis is not applicable. Thus, with the new method, routinely recorded postsynaptic currents could be used to study the properties of synaptic receptors in their native biochemical environment.
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Affiliation(s)
- Andrey Stepanyuk
- Laboratory of Molecular Biophysics, Bogomoletz Institute of Physiology Kiev, Ukraine ; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology Kiev, Ukraine
| | - Anya Borisyuk
- Laboratory of Molecular Biophysics, Bogomoletz Institute of Physiology Kiev, Ukraine ; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology Kiev, Ukraine
| | - Pavel Belan
- Laboratory of Molecular Biophysics, Bogomoletz Institute of Physiology Kiev, Ukraine ; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology Kiev, Ukraine
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Regional Diversity and Developmental Dynamics of the AMPA-Receptor Proteome in the Mammalian Brain. Neuron 2014; 84:41-54. [DOI: 10.1016/j.neuron.2014.08.044] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2014] [Indexed: 12/20/2022]
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Haering SC, Tapken D, Pahl S, Hollmann M. Auxiliary subunits: shepherding AMPA receptors to the plasma membrane. MEMBRANES 2014; 4:469-90. [PMID: 25110960 PMCID: PMC4194045 DOI: 10.3390/membranes4030469] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/17/2014] [Accepted: 07/25/2014] [Indexed: 11/24/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) are tetrameric ligand-gated cation channels that mediate excitatory signal transmission in the central nervous system (CNS) of vertebrates. The members of the iGluR subfamily of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs) mediate most of the fast excitatory signal transmission, and their abundance in the postsynaptic membrane is a major determinant of the strength of excitatory synapses. Therefore, regulation of AMPAR trafficking to the postsynaptic membrane is an important constituent of mechanisms involved in learning and memory formation, such as long-term potentiation (LTP) and long-term depression (LTD). Auxiliary subunits play a critical role in the facilitation and regulation of AMPAR trafficking and function. The currently identified auxiliary subunits of AMPARs are transmembrane AMPA receptor regulatory proteins (TARPs), suppressor of lurcher (SOL), cornichon homologues (CNIHs), synapse differentiation-induced gene I (SynDIG I), cysteine-knot AMPAR modulating proteins 44 (CKAMP44), and germ cell-specific gene 1-like (GSG1L) protein. In this review we summarize our current knowledge of the modulatory influence exerted by these important but still underappreciated proteins.
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Affiliation(s)
- Simon C Haering
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
| | - Daniel Tapken
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
| | - Steffen Pahl
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
| | - Michael Hollmann
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
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A protein synthesis-dependent mechanism sustains calcium-permeable AMPA receptor transmission in nucleus accumbens synapses during withdrawal from cocaine self-administration. J Neurosci 2014; 34:3095-100. [PMID: 24553949 DOI: 10.1523/jneurosci.4940-13.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Extended-access cocaine self-administration results in withdrawal-dependent incubation of cocaine craving. Rats evaluated after ∼1 month of withdrawal from such regimens ("incubated rats") exhibit changes in medium spiny neurons (MSNs) of the nucleus accumbens (NAc) that include accumulation of Ca(2+)-permeable AMPA receptors (CP-AMPARs) and a switch in group I metabotropic glutamate receptor (mGluR)-mediated suppression of synaptic transmission from mGluR5-dependent to mGluR1-dependent. To determine the role of protein synthesis in mediating these adaptations, we conducted whole-cell patch-clamp recordings in NAc core MSNs of "incubated rats" in the presence of translational inhibitors (anisomycin, cycloheximide, rapamycin) or the transcriptional inhibitor actinomycin-D. The contribution of CP-AMPARs to synaptic transmission was determined by the rectification index and the sensitivity to the CP-AMPAR antagonist 1-naphthyl acetyl spermine. We found that CP-AMPAR-mediated transmission in the NAc of "incubated rats" was reduced to levels comparable to those found in saline control rats when brain slices were treated with translational inhibitors, whereas actinomycin-D had no effect. We also investigated the effect of protein translation inhibitors on the switch of mGluR function in MSNs of "incubated rats" using the group I mGluR agonist (S)-3,5-dihydroxyphenylglycine in combination with either an mGluR1 (LY367385) or an mGluR5 (3-[(2-methyl-4-thiazolyl)ethynyl]pyridine) antagonist. Data revealed that inhibition of protein translation eliminated the mGluR1-mediated inhibition and restored the mGluR5 responsiveness to a state functionally similar to that of saline control rats. Together, these results suggest that aberrant regulation of local protein synthesis contributes to the maintenance of adaptations accrued at NAc MSN synapses during incubation of cocaine craving.
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Subunit-specific trafficking mechanisms regulating the synaptic expression of Ca(2+)-permeable AMPA receptors. Semin Cell Dev Biol 2013; 27:14-22. [PMID: 24342448 DOI: 10.1016/j.semcdb.2013.12.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
AMPA receptors are the main excitatory neurotransmitter receptor in the brain, and hence regulating the number or properties of synaptic AMPA receptors brings about critical changes in synaptic transmission. Synaptic plasticity is thought to underlie learning and memory, and can be brought about by decreasing or increasing the number of AMPA receptors localised to synaptic sites by precisely regulating AMPA receptor trafficking. AMPA receptors are tetrameric assemblies of subunits GluA1-4, and the vast majority are GluA1/2 and GluA2/3 heteromers. The inclusion of GluA2 subunit is critical because it renders the AMPA receptor channel impermeable to Ca(2+) ions. The vast majority of synaptic AMPA receptors in the brain contain GluA2, but relatively recent discoveries indicate that an increasing number of specific forms of synaptic plasticity involve not only an alteration of the number of synaptic AMPA receptors, but also changes to their GluA2 content. The resulting change in AMPA receptor Ca(2+) permeability clearly has profound consequences for synaptic transmission and intracellular signalling events. The subunit-specific trafficking mechanisms that cause such changes represent an emerging field of research with implications for an increasing number of physiological or pathological situations, and are the topic of this review.
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