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Nakahata Y, Eto K, Murakoshi H, Watanabe M, Kuriu T, Hirata H, Moorhouse AJ, Ishibashi H, Nabekura J. Activation-Dependent Rapid Postsynaptic Clustering of Glycine Receptors in Mature Spinal Cord Neurons. eNeuro 2017; 4:ENEURO.0194-16.2017. [PMID: 28197549 PMCID: PMC5292596 DOI: 10.1523/eneuro.0194-16.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 01/05/2017] [Accepted: 01/17/2017] [Indexed: 12/02/2022] Open
Abstract
Inhibitory synapses are established during development but continue to be generated and modulated in strength in the mature nervous system. In the spinal cord and brainstem, presynaptically released inhibitory neurotransmitter dominantly switches from GABA to glycine during normal development in vivo. While presynaptic mechanisms of the shift of inhibitory neurotransmission are well investigated, the contribution of postsynaptic neurotransmitter receptors to this shift is not fully elucidated. Synaptic clustering of glycine receptors (GlyRs) is regulated by activation-dependent depolarization in early development. However, GlyR activation induces hyperpolarization after the first postnatal week, and little is known whether and how presynaptically released glycine regulates postsynaptic receptors in a depolarization-independent manner in mature developmental stage. Here we developed spinal cord neuronal culture of rodents using chronic strychnine application to investigate whether initial activation of GlyRs in mature stage could change postsynaptic localization of GlyRs. Immunocytochemical analyses demonstrate that chronic blockade of GlyR activation until mature developmental stage resulted in smaller clusters of postsynaptic GlyRs that could be enlarged upon receptor activation for 1 h in the mature stage. Furthermore, live cell-imaging techniques show that GlyR activation decreases its lateral diffusion at synapses, and this phenomenon is dependent on PKC, but neither Ca2+ nor CaMKII activity. These results suggest that the GlyR activation can regulate receptor diffusion and cluster size at inhibitory synapses in mature stage, providing not only new insights into the postsynaptic mechanism of shifting inhibitory neurotransmission but also the inhibitory synaptic plasticity in mature nervous system.
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Affiliation(s)
- Yoshihisa Nakahata
- Division of Homeostatic Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
| | - Kei Eto
- Division of Homeostatic Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
| | - Hideji Murakoshi
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
- Supportive Center for Brain Research, National Institute for Physiological Science, Okazaki 444-8585, Japan
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi 332-0012, Japan
| | - Miho Watanabe
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Toshihiko Kuriu
- Department of Neurophysiology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima 769-2193, Japan
| | - Hiromi Hirata
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi 332-0012, Japan
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima 411-8540, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima 411-8540, Japan
- Department of Chemistry and Biological Science, Graduate School of Science and Engineering, Aoyama Gakuin University, Sagamihara 252-5258, Japan
| | - Andrew J. Moorhouse
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney 2052, Australia
| | - Hitoshi Ishibashi
- Division of Homeostatic Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
- Department of Physiology, Kitasato University School of Allied Health Sciences, Sagamihara 252-0373, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
- CREST, Japan Science and Technology Agency (JST), Kawaguchi 332-0012, Japan
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Notelaers K, Rocha S, Paesen R, Swinnen N, Vangindertael J, Meier JC, Rigo JM, Ameloot M, Hofkens J. Membrane distribution of the glycine receptor α3 studied by optical super-resolution microscopy. Histochem Cell Biol 2014; 142:79-90. [PMID: 24553792 DOI: 10.1007/s00418-014-1197-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2014] [Indexed: 11/24/2022]
Abstract
In this study, the effect of glycine receptor (GlyR) α3 alternative RNA splicing on the distribution of receptors in the membrane of human embryonic kidney 293 cells is investigated using optical super-resolution microscopy. Direct stochastic optical reconstruction microscopy is used to image both α3K and α3L splice variants individually and together using single- and dual-color imaging. Pair correlation analysis is used to extract quantitative measures from the resulting images. Autocorrelation analysis of the individually expressed variants reveals clustering of both variants, yet with differing properties. The cluster size is increased for α3L compared to α3K (mean radius 92 ± 4 and 56 ± 3 nm, respectively), yet an even bigger difference is found in the cluster density (9,870 ± 1,433 and 1,747 ± 200 μm(-2), respectively). Furthermore, cross-correlation analysis revealed that upon co-expression, clusters colocalize on the same spatial scales as for individually expressed receptors (mean co-cluster radius 94 ± 6 nm). These results demonstrate that RNA splicing determines GlyR α3 membrane distribution, which has consequences for neuronal GlyR physiology and function.
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Affiliation(s)
- Kristof Notelaers
- Biomedical Research Institute, Hasselt University and School of Life Sciences, Transnational University Limburg, Agoralaan Gebouw C, 3590, Diepenbeek, Belgium
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Ganser LR, Dallman JE. Glycinergic synapse development, plasticity, and homeostasis in zebrafish. Front Mol Neurosci 2009; 2:30. [PMID: 20126315 PMCID: PMC2815536 DOI: 10.3389/neuro.02.030.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Accepted: 11/26/2009] [Indexed: 11/13/2022] Open
Abstract
The zebrafish glial glycine transporter 1 (GlyT1) mutant provides an animal model in which homeostatic plasticity at glycinergic synapses restores rhythmic motor behaviors. GlyT1 mutants, initially paralyzed by the build-up of the inhibitory neurotransmitter glycine, stage a gradual recovery that is associated with reductions in the strength of evoked glycinergic responses. Gradual motor recovery suggests sequential compensatory mechanisms that culminate in the down-regulation of the neuronal glycine receptor. However, how motor recovery is initiated and how other forms of plasticity contribute to behavioral recovery are still outstanding questions that we discuss in the context of (1) glycinergic synapses as they function in spinal circuits that produce rhythmic motor behaviors, (2) the proteins involved in regulating glycinergic synaptic strength, (3) current models of glycinergic synaptogenesis, and (4) plasticity mechanisms that modulate the strength of glycinergic synapses. Concluding remarks (5) explore the potential for distinct plasticity mechanisms to act in concert at different spatial and temporal scales to achieve a dynamic stability that results in balanced motor behaviors.
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Affiliation(s)
- Lisa R Ganser
- Department of Biology, University of Miami Coral Gables, FL, USA
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Kandler K, Clause A, Noh J. Tonotopic reorganization of developing auditory brainstem circuits. Nat Neurosci 2009; 12:711-7. [PMID: 19471270 DOI: 10.1038/nn.2332] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 04/07/2009] [Indexed: 02/08/2023]
Abstract
A fundamental organizing principle of auditory brain circuits is tonotopy, the orderly representation of the sound frequency to which neurons are most sensitive. Tonotopy arises from the coding of frequency along the cochlea and the topographic organization of auditory pathways. The mechanisms that underlie the establishment of tonotopy are poorly understood. In auditory brainstem pathways, topographic precision is present at very early stages in development, which may suggest that synaptic reorganization contributes little to the construction of precise tonotopic maps. Accumulating evidence from several brainstem nuclei, however, is now changing this view by demonstrating that developing auditory brainstem circuits undergo a marked degree of refinement on both a subcellular and circuit level.
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Affiliation(s)
- Karl Kandler
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Eye and Ear Institute, Pittsburgh, Pennsylvania, USA.
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Pape JR, Bertrand SS, Lafon P, Odessa MF, Chaigniau M, Stiles JK, Garret M. Expression of GABA(A) receptor alpha3-, theta-, and epsilon-subunit mRNAs during rat CNS development and immunolocalization of the epsilon subunit in developing postnatal spinal cord. Neuroscience 2009; 160:85-96. [PMID: 19249336 DOI: 10.1016/j.neuroscience.2009.02.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 02/03/2009] [Accepted: 02/19/2009] [Indexed: 12/13/2022]
Abstract
Ionotropic GABA(A) receptors are heteromeric structures composed of a combination of five from at least 16 different subunits. Subunit genes are expressed in distinct cell types at specific times during development. The most abundant native GABA(A) receptors consist of alpha1-, beta2-, and gamma2-subunits that are co-expressed in numerous brain areas. alpha3-, theta-, And epsilon-subunits are clustered on the X chromosome and show striking overlapping expression patterns throughout the adult rat brain. To establish whether these subunits are temporally and spatially co-expressed, we used in situ hybridization to analyze their expression throughout rat development from embryonic stage E14 to postnatal stage P12. Each transcript exhibited a unique or a shared regional and temporal developmental expression profile. The thalamic expression pattern evolved from a restricted expression of epsilon and theta transcripts before birth, to a theta and alpha3 expression at birth, and finally to a grouped epsilon, theta and alpha3 expression postpartum. However, strong similarities occurred, such as a grouped expression of the three subunits within the hypothalamus, tegmentum and pontine nuclei throughout the developmental process. At early stages of development (E17), epsilon and theta appeared to have a greater spatial distribution before the dominance of the alpha3 subunit transcript around birth. We also revealed expression of alpha3, theta, and epsilon in the developing spinal cord and identified neurons that express epsilon in the postnatal dorsal horn, intermediolateral column and motoneurons. Our findings suggest that various combinations of alpha3-, theta- and epsilon-subunits may be assembled at a regional and developmental level in the brain.
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Affiliation(s)
- J-R Pape
- Université de Bordeaux, CNRS, UMR 5228, France
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Abstract
Renshaw cell properties have been studied extensively for over 50 years, making them a uniquely well-defined class of spinal interneuron. Recent work has revealed novel ways to identify Renshaw cells in situ and this in turn has promoted a range of studies that have determined their ontogeny and organization of synaptic inputs in unprecedented detail. In this review we illustrate how mature Renshaw cell properties and connectivity arise through a combination of activity-dependent and genetically specified mechanisms. These new insights should aid the development of experimental strategies to manipulate Renshaw cells in spinal circuits and clarify their role in modulating motor output.
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Affiliation(s)
- Francisco J Alvarez
- Department of Neuroscience, Cell Biology & Physiology, Boonshoft School of Medicine, Wright State University, 3640 Col. Glenn Hwy, Dayton, OH 45435, USA.
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Swanwick CC, Murthy NR, Mtchedlishvili Z, Sieghart W, Kapur J. Development of gamma-aminobutyric acidergic synapses in cultured hippocampal neurons. J Comp Neurol 2006; 495:497-510. [PMID: 16498682 PMCID: PMC2742963 DOI: 10.1002/cne.20897] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The formation and maturation of gamma-aminobutyric acid (GABA)-ergic synapses was studied in cultured hippocampal pyramidal neurons by both performing immunocytochemistry for GABAergic markers and recording miniature inhibitory postsynaptic currents (mIPSCs). Nascent GABAergic synapses appeared between 3 and 8 days in vitro (DIV), with GABAA receptor subunit clusters appearing first, followed by GAD-65 puncta, then functional synapses. The number of GABAergic synapses increased from 7 to 14 DIV, with a corresponding increase in frequency of mIPSCs. Moreover, these new GABAergic synapses formed on neuronal processes farther from the soma, contributing to decreased mIPSC amplitude and slowed mIPSC 19-90% rise time. The mIPSC decay quickened from 7 to 14 DIV, with a parallel change in the distribution of the alpha5 subunit from diffuse expression at 7 DIV to clustered expression at 14 DIV. These alpha5 clusters were mostly extrasynaptic. The alpha1 subunit was expressed as clusters in none of the neurons at 7 DIV, in 20% at 14 DIV, and in 80% at 21 DIV. Most of these alpha1 clusters were expressed at GABAergic synapses. In addition, puncta of GABA transporter 1 (GAT-1) were localized to GABAergic synapses at 14 DIV but were not expressed at 7 DIV. These studies demonstrate that mIPSCs appear after pre- and postsynaptic elements are in place. Furthermore, the process of maturation of GABAergic synapses involves increased synapse formation at distal processes, expression of new GABAA receptor subunits, and GAT-1 expression at synapses; these changes are reflected in altered frequency, kinetics, and drug sensitivity of mIPSCs.
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Affiliation(s)
| | - Namita R. Murthy
- College of Arts and Sciences, University of Virginia, Charlottesville, VA 22908, USA
| | | | - Werner Sieghart
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Jaideep Kapur
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Dept. of Neurology, University of Virginia, Charlottesville, VA 22908, USA
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Christie SB, Li RW, Miralles CP, Yang BY, De Blas AL. Clustered and non-clustered GABAA receptors in cultured hippocampal neurons. Mol Cell Neurosci 2005; 31:1-14. [PMID: 16181787 DOI: 10.1016/j.mcn.2005.08.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 08/17/2005] [Accepted: 08/23/2005] [Indexed: 12/31/2022] Open
Abstract
In cultured hippocampal neurons, gamma2 subunit-containing GABA(A) Rs form large postsynaptic clusters at GABAergic synapses and small clusters outside GABAergic synapses. We now show that a pool of non-clustered gamma2 subunit-containing GABA(A) Rs are also present at the cell surface. We also demonstrate that myc- or EGFP-tagged gamma2, alpha2, beta3 or alpha1 subunits expressed in these neurons assemble with endogenous subunits, forming GABA(A) Rs that target large postsynaptic clusters, small clusters outside GABAergic synapses or a pool of non-clustered surface GABA(A) Rs. In contrast, myc- or EGFP-tagged delta subunits only form non-clustered GABA(A) Rs, which can be induced to form clusters by antibody capping. A myc-tagged chimeric gamma2 subunit possessing the large intracellular loop (IL) of the delta-subunit IL (myc gamma2S/delta-IL) assembled into GABA(A) Rs, but it did not form clusters, therefore behaving like the delta subunit. Thus, the large intracellular loops of gamma2 and delta play an important role in determining the synaptic clustering/non-clustering capacity of the GABA(A) Rs.
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Affiliation(s)
- S B Christie
- Department of Physiology and Neurobiology, University of Connecticut, 3107 Horsebarn Hill Rd., U-4156, Storrs, CT 06269, USA
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Luján R, Shigemoto R, López-Bendito G. Glutamate and GABA receptor signalling in the developing brain. Neuroscience 2005; 130:567-80. [PMID: 15590141 DOI: 10.1016/j.neuroscience.2004.09.042] [Citation(s) in RCA: 284] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2004] [Indexed: 10/26/2022]
Abstract
Our understanding of the role played by neurotransmitter receptors in the developing brain has advanced in recent years. The major excitatory and inhibitory neurotransmitters in the brain, glutamate and GABA, activate both ionotropic (ligand-gated ion channels) and metabotropic (G protein-coupled) receptors, and are generally associated with neuronal communication in the mature brain. However, before the emergence of their role in neurotransmission in adulthood, they also act to influence earlier developmental events, some of which occur prior to synapse formation: such as proliferation, migration, differentiation or survival processes during neural development. To fulfill these actions in the constructing of the nervous system, different types of glutamate and GABA receptors need to be expressed both at the right time and at the right place. The identification by molecular cloning of 16 ionotropic glutamate receptor subunits, eight metabotropic glutamate receptor subtypes, 21 ionotropic and two metabotropic GABA receptor subunits, some of which exist in alternatively splice variants, has enriched our appreciation of how molecular diversity leads to functional diversity in the brain. It now appears that many different types of glutamate and GABA receptor subunits have prominent expression in the embryonic and/or postnatal brain, whereas others are mainly present in the adult brain. Although the significance of this differential expression of subunits is not fully understood, it appears that the change in subunit composition is essential for normal development in particular brain regions. This review focuses on emerging information relating to the expression and role of glutamatergic and GABAergic neurotransmitter receptors during prenatal and postnatal development.
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Affiliation(s)
- R Luján
- Facultad de Medicina and Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Campus Biosanitario, Avda. de Almansa s/n, 02006 Albacete, Spain.
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Abstract
The mechanisms that govern synapse formation and elimination are fundamental to our understanding of neural development and plasticity. The wiring of neural circuitry requires that vast numbers of synapses be formed in a relatively short time. The subsequent refinement of neural circuitry involves the formation of additional synapses coincident with the disassembly of previously functional synapses. There is increasing evidence that activity-dependent plasticity also involves the formation and disassembly of synapses. While we are gaining insight into the mechanisms of both synapse assembly and disassembly, we understand very little about how these phenomena are related to each other and how they might be coordinately controlled to achieve the precise patterns of synaptic connectivity in the nervous system. Here, we review our current understanding of both synapse assembly and disassembly in an effort to unravel the relationship between these fundamental developmental processes.
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Affiliation(s)
- Yukiko Goda
- MRC Cell Biology Unit and Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom.
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