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Castillo-Vazquez SK, Massieu L, Rincón-Heredia R, García-de la Torre P, Quiroz-Baez R, Gomez-Verjan JC, Rivero-Segura NA. Glutamatergic Neurotransmission in Aging and Neurodegenerative Diseases: A Potential Target to Improve Cognitive Impairment in Aging. Arch Med Res 2024; 55:103039. [PMID: 38981341 DOI: 10.1016/j.arcmed.2024.103039] [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: 01/11/2024] [Revised: 06/10/2024] [Accepted: 06/26/2024] [Indexed: 07/11/2024]
Abstract
Aging is characterized by the decline in many of the individual's capabilities. It has been recognized that the brain undergoes structural and functional changes during aging that are occasionally associated with the development of neurodegenerative diseases. In this sense, altered glutamatergic neurotransmission, which involves the release, binding, reuptake, and degradation of glutamate (Glu) in the brain, has been widely studied in physiological and pathophysiological aging. In particular, changes in glutamatergic neurotransmission are exacerbated during neurodegenerative diseases and are associated with cognitive impairment, characterized by difficulties in memory, learning, concentration, and decision-making. Thus, in the present manuscript, we aim to highlight the relevance of glutamatergic neurotransmission during cognitive impairment to develop novel strategies to prevent, ameliorate, or delay cognitive decline. To achieve this goal, we provide a comprehensive review of the changes reported in glutamatergic neurotransmission components, such as Glu transporters and receptors during physiological aging and in the most studied neurodegenerative diseases. Finally, we describe the current therapeutic strategies developed to target glutamatergic neurotransmission.
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Affiliation(s)
- Selma Karime Castillo-Vazquez
- Dirección de Investigación, Instituto Nacional de Geriatría, Mexico City, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Lourdes Massieu
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ruth Rincón-Heredia
- Unidad de Imagenología, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Paola García-de la Torre
- 4 Unidad de Investigación Epidemiológica y en Servicios de Salud, Área de Envejecimiento, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City Mexico
| | - Ricardo Quiroz-Baez
- Dirección de Investigación, Instituto Nacional de Geriatría, Mexico City, Mexico
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Midorikawa M. Pathway-specific maturation of presynaptic functions of the somatosensory thalamus. Neurosci Res 2022; 181:1-8. [DOI: 10.1016/j.neures.2022.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 02/05/2023]
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Cerebellum and Emotion Memory. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1378:53-73. [DOI: 10.1007/978-3-030-99550-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Dutta P, Bharti P, Kumar J, Maiti S. Role of actin cytoskeleton in the organization and function of ionotropic glutamate receptors. Curr Res Struct Biol 2021; 3:277-289. [PMID: 34766008 PMCID: PMC8569634 DOI: 10.1016/j.crstbi.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/04/2021] [Accepted: 10/09/2021] [Indexed: 12/22/2022] Open
Abstract
Neural networks with precise connection are compulsory for learning and memory. Various cellular events occur during the genesis of dendritic spines to their maturation, synapse formation, stabilization of the synapse, and proper signal transmission. The cortical actin cytoskeleton and its multiple regulatory proteins are crucial for the above cellular events. The different types of ionotropic glutamate receptors (iGluRs) present on the postsynaptic density (PSD) are also essential for learning and memory. Interaction of the iGluRs in association of their auxiliary proteins with actin cytoskeleton regulated by actin-binding proteins (ABPs) are required for precise long-term potentiation (LTP) and long-term depression (LTD). There has been a quest to understand the mechanistic detail of synapse function involving these receptors with dynamic actin cytoskeleton. A major, emerging area of investigation is the relationship between ABPs and iGluRs in synapse development. In this review we have summarized the current understanding of iGluRs functioning with respect to the actin cytoskeleton, scaffolding proteins, and their regulators. The AMPA, NMDA, Delta and Kainate receptors need the stable underlying actin cytoskeleton to anchor through synaptic proteins for precise synapse formation. The different types of ABPs present in neurons play a critical role in dynamizing/stabilizing the actin cytoskeleton needed for iGluRs function.
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Affiliation(s)
- Priyanka Dutta
- National Centre for Cell Science, Pune, Maharashtra, 411007, India
| | - Pratibha Bharti
- National Centre for Cell Science, Pune, Maharashtra, 411007, India
| | - Janesh Kumar
- National Centre for Cell Science, Pune, Maharashtra, 411007, India
| | - Sankar Maiti
- Indian Institute of Science Education and Research, Kolkata, 741246, India
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Chin AC, Yovanno RA, Wied TJ, Gershman A, Lau AY. D-Serine Potently Drives Ligand-Binding Domain Closure in the Ionotropic Glutamate Receptor GluD2. Structure 2020; 28:1168-1178.e2. [PMID: 32735769 DOI: 10.1016/j.str.2020.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/24/2020] [Accepted: 07/10/2020] [Indexed: 12/15/2022]
Abstract
Despite their classification as ionotropic glutamate receptors, GluD receptors are not functional ligand-gated ion channels and do not bind glutamate. GluD2 receptors bind D-serine and coordinate transsynaptic complexes that regulate synaptic plasticity. Instead of opening the ion channel pore, mechanical tension produced from closure of GluD2 ligand-binding domains (LBDs) drives conformational rearrangements for non-ionotropic signaling. We report computed conformational free energy landscapes for the GluD2 LBD in apo and D-serine-bound states. Unexpectedly, the conformational free energy associated with GluD2 LBD closure upon D-serine binding is greater than that for AMPA, NMDA, and kainate receptor LBDs upon agonist binding. This excludes insufficient force generation as an explanation for lack of ion channel activity in GluD2 receptors and suggests that non-ionotropic conformational rearrangements do more work than pore opening. We also report free energy landscapes for GluD2 LBD harboring a neurodegenerative mutation and demonstrate selective stabilization of closed conformations in the apo state.
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Affiliation(s)
- Alfred C Chin
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Remy A Yovanno
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tyler J Wied
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ariel Gershman
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Albert Y Lau
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Cendelin J, Purkartova Z, Kubik J, Ulbricht E, Tichanek F, Kolinko Y. Long-Term Development of Embryonic Cerebellar Grafts in Two Strains of Lurcher Mice. THE CEREBELLUM 2019; 17:428-437. [PMID: 29450804 DOI: 10.1007/s12311-018-0928-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
For many degenerative cerebellar diseases, currently, no effective treatment that would substantially restore cerebellar functions is available. Neurotransplantation could be a promising therapy for such cases. Nevertheless, there are still severe limitations for routine clinical use. The aim of the work was to assess volume and morphology and functional impact on motor skills of an embryonic cerebellar graft injected in the form of cell suspension in Lurcher mutant and wild-type mice of the B6CBA and C3H strains after a 6-month survival period. The grafts survived in the majority of the mice. In both B6CBA and C3H Lurcher mice, most of the grafts were strictly delimited with no tendency to invade the host cerebellum, while in wild-type mice, graft-derived Purkinje cells colonized the host's cerebellum. In C3H Lurcher mice, but not in B6CBA Lurchers, the grafts had smaller volume than in their wild-type counterparts. C3H wild-type mice had significantly larger grafts than B6CBA wild-type mice. No positive effect of the transplantation on performance in the rotarod test was observed. The findings suggest that the niche of the Lurcher mutant cerebellum has a negative impact on integration of grafted cells. This factor seems to be limiting for specific functional effects of the transplantation therapy in this mouse model of cerebellar degeneration.
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Affiliation(s)
- Jan Cendelin
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic.
- Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic.
| | - Zdenka Purkartova
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic
| | - Jakub Kubik
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic
| | - Erik Ulbricht
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic
| | - Filip Tichanek
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic
- Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic
| | - Yaroslav Kolinko
- Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University, Karlovarska 48, 301 66, Plzen, Czech Republic
- Laboratory of Quantitative Histology, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Karlovarska 48, 301 66, Plzen, Czech Republic
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Wied TJ, Chin AC, Lau AY. High Conformational Variability in the GluK2 Kainate Receptor Ligand-Binding Domain. Structure 2019; 27:189-195.e2. [PMID: 30482727 PMCID: PMC6363114 DOI: 10.1016/j.str.2018.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/26/2018] [Accepted: 09/19/2018] [Indexed: 10/28/2022]
Abstract
The kainate family of ionotropic glutamate receptors (iGluRs) mediates pre- and postsynaptic neurotransmission. Previously computed conformational potentials of mean force (PMFs) for iGluR ligand-binding domains (LBDs) revealed subtype-dependent conformational differences between α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartic acid (NMDA) iGluR subfamilies. Here we report PMFs for the kainate receptor GluK2 in apo and glutamate-bound states. Apo and glutamate-bound GluK2 LBDs preferentially access closed-cleft conformations. Apo GluK2 exhibits a surprisingly high degree of conformational flexibility, accessing open and closed states. Comparing across iGluR subtypes, these results are similar to glycine-binding GluN1 and GluN3A NMDA subunits and differ from glutamate-binding GluA2 and GluN2A subunits. To test the contribution of cross-lobe interactions on closed-cleft LBD stability, we computed PMFs for two GluK2 mutants, D462A and D656S. D462A, but not D656S, weakens closed-cleft conformations of the glutamate-bound LBD. Theoretical Boltzmann-weighted small-angle X-ray scattering profiles improve agreement with experimental results compared with calculations from the LBD crystal structure alone.
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Affiliation(s)
- Tyler J Wied
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alfred C Chin
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Albert Y Lau
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Suriano CM, Bodznick D. Evidence for generative homology of cerebellum and cerebellum-like structures in an elasmobranch fish based onPax6, Cbln1andGrid2expression. J Comp Neurol 2018; 526:2187-2203. [DOI: 10.1002/cne.24473] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/27/2022]
Affiliation(s)
| | - David Bodznick
- Biology Department; Wesleyan University; Middletown Connecticut
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9
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Pre- and postsynaptic ionotropic glutamate receptors in the auditory system of mammals. Hear Res 2018; 362:1-13. [DOI: 10.1016/j.heares.2018.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/16/2018] [Accepted: 02/21/2018] [Indexed: 01/22/2023]
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Zanjani HS, Vogel MW, Mariani J. Deletion of the GluRδ2 Receptor in the Hotfoot Mouse Mutant Causes Granule Cell Loss, Delayed Purkinje Cell Death, and Reductions in Purkinje Cell Dendritic Tree Area. THE CEREBELLUM 2017; 15:755-766. [PMID: 26607150 DOI: 10.1007/s12311-015-0748-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recent studies have found that in the cerebellum, the δ2 glutamate receptor (GluRδ2) plays a key role in regulating the differentiation of parallel fiber-Purkinje synapses and mediating key physiological functions in the granule cell-Purkinje cell circuit. In the hotfoot mutant or GluRδ2 knockout mice, the absence of GluRδ2 expression results in impaired motor-related tasks, ataxia, and disruption of long-term depression at parallel fiber-Purkinje cell synapses. The goal of this study was to determine the long-term consequences of deletion of GluRδ2 expression in the hotfoot mutant (GluRδ2 ho/ho ) on Purkinje and granule cell survival and Purkinje cell dendritic differentiation. Quantitative estimates of Purkinje and granule cell numbers in 3-, 12-, and 20-month-old hotfoot mutants and wild-type controls showed that Purkinje cell numbers are within control values at 3 and 12 months in the hotfoot mutant but reduced by 20 % at 20 months compared with controls. In contrast, the number of granule cells is significantly reduced from 3 months onwards in GluRδ2 ho/ho mutant mice compared to wild-type controls. Although the overall structure of Purkinje cell dendrites does not appear to be altered, there is a significant 27 % reduction in the cross-sectional area of Purkinje cell dendritic trees in the 20-month-old GluRδ2 ho/ho mutants. The interpretation of the results is that the GluRδ2 receptor plays an important role in the long-term organization of the granule-Purkinje cell circuit through its involvement in the regulation of parallel fiber-Purkinje cell synaptogenesis and in the normal functioning of this critical cerebellar circuit.
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Affiliation(s)
- Hadi S Zanjani
- Sorbonne Universités UPMC Univ. Paris 06, IBPS, UMR 8256, Biological Adaptation and Ageing, B2A, 75005, Paris, France.,CNRS, UMR 8256, B2A, F-75005, Paris, France
| | - Michael W Vogel
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD, 21228, USA.
| | - Jean Mariani
- Sorbonne Universités UPMC Univ. Paris 06, IBPS, UMR 8256, Biological Adaptation and Ageing, B2A, 75005, Paris, France.,CNRS, UMR 8256, B2A, F-75005, Paris, France.,Institut de la Longévité, APHP, DHU Fast, 94205, Ivry-Sur-Seine, France
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Neuroligins Are Selectively Essential for NMDAR Signaling in Cerebellar Stellate Interneurons. J Neurosci 2017; 36:9070-83. [PMID: 27581450 DOI: 10.1523/jneurosci.1356-16.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/16/2016] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Neuroligins are postsynaptic cell-adhesion molecules that contribute to synapse specification. However, many other postsynaptic cell-adhesion molecules are known and the relative contributions of neuroligins versus other such molecules in different types of synapses and neurons remains largely unknown. Here, we have studied the role of neuroligins in cerebellar stellate interneurons that participate in a well defined circuit that converges on Purkinje cells as the major output neurons of cerebellar cortex. By crossing triple conditional knock-out (cKO) mice targeting all three major neuroligins [neuroligin-1 to neuroligin-3 (NL123)] with parvalbumin-Cre (PV-Cre) transgenic mice, we deleted neuroligins from inhibitory cerebellar interneurons and Purkinje cells, allowing us to study the effects of neuroligin deletions on cerebellar stellate cell synapses by electrophysiology in acute slices. PV-Cre/NL123 cKO mice did not exhibit gross alterations of cerebellar structure or cerebellar interneuron morphology. Strikingly, electrophysiological recordings in stellate cells from these PV-Cre/NL123 cKO mice revealed a large decrease in NMDAR-mediated excitatory synaptic responses, which, in stellate cells, are largely extrasynaptic, without a change in AMPA-receptor-mediated responses. Parallel analyses in PV-Cre/NL1 mice that are single NL1 cKO mice uncovered the same phenotype, demonstrating that NL1 is responsible for recruiting extrasynaptic NMDARs. Moreover, we observed only a modest impairment in inhibitory synaptic responses in stellate cells lacking NL123 despite a nearly complete suppression of inhibitory synaptic transmission in Purkinje cells by the same genetic manipulation. Our results suggest that, unlike other types of neurons investigated, neuroligins are selectively essential in cerebellar stellate interneurons for enabling the function of extrasynaptic NMDARs. SIGNIFICANCE STATEMENT Neuroligins are postsynaptic cell-adhesion molecules genetically linked to autism. However, the contributions of neuroligins to interneuron functions remain largely unknown. Here, we analyzed the role of neuroligins in cerebellar stellate interneurons. We deleted neuroligin-1, neuroligin-2, and neuroligin-3, the major cerebellar neuroligin isoforms, from stellate cells in triple NL123 conditional knock-out mice and analyzed synaptic responses by acute slice electrophysiology. We find that neuroligins are selectively essential for extrasynaptic NMDAR-mediated signaling, but dispensable for both AMPAR-mediated and inhibitory synaptic transmission. Our results reveal a critical and selective role for neuroligins in the regulation of NMDAR responses in cerebellar stellate interneurons.
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Yuzaki M, Aricescu AR. A GluD Coming-Of-Age Story. Trends Neurosci 2017; 40:138-150. [PMID: 28110935 DOI: 10.1016/j.tins.2016.12.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 01/02/2023]
Abstract
The GluD1 and GluD2 receptors form the GluD ionotropic glutamate receptor (iGluR) subfamily. Without known endogenous ligands, they have long been referred to as 'orphan' and remained enigmatic functionally. Recent progress has, however, radically changed this view. Both GluD receptors are expressed in wider brain regions than originally thought. Human genetic studies and analyses of knockout mice have revealed their involvement in multiple neurodevelopmental and psychiatric disorders. The discovery of endogenous ligands, together with structural investigations, has opened the way towards a mechanistic understanding of GluD signaling at central nervous system synapses. These studies have also prompted the hypothesis that all iGluRs, and potentially other neurotransmitter receptors, rely on the cooperative binding of extracellular small-molecule and protein ligands for physiological signaling.
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Affiliation(s)
- Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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14
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The Purkinje cell as a model of synaptogenesis and synaptic specificity. Brain Res Bull 2016; 129:12-17. [PMID: 27721030 DOI: 10.1016/j.brainresbull.2016.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/28/2016] [Accepted: 10/05/2016] [Indexed: 01/03/2023]
Abstract
Since the groundbreaking work of Ramon y Cajal, the cerebellar Purkinje cell has always represented an ideal model for studying the organization, development and function of synaptic circuits. Purkinje cells receive distinct types of glutamatergic and GABAergic synapses, each characterized by exquisite sub-cellular and molecular specificity. The formation and refinement of these connections results from a temporally-regulated sequence of events that involves molecular interactions between distinct sets of secreted and surface proteins, as well as activity-dependent competition between converging inputs. Insights into the mechanisms controlling synaptic specificity in Purkinje cells may help understand synapse development also in other brain regions and disclose circuit abnormalities that underlie neurodevelopmental disorders.
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Abstract
In addition to coordinating movement, the cerebellum participates in motor learning, emotional behavior, and fear memory. Fear learning is reflected in a change of autonomic and somatic responses, such as heart rate and freezing, elicited by a neutral stimulus that has been previously paired with a painful one. Manipulation of the vermis affects these responses, and its reversible inactivation during the consolidation period impairs fear memory. The neural correlate of cerebellar involvement in fear consolidation is provided by a behaviorally induced long-term increase of synaptic efficacy between parallel fibers and a Purkinje cell. Similar synaptic changes after fear conditioning are well documented in the amygdala and hippocampus, providing a link between emotional experiences and changes in neural activity. In addition, in hotfoot mice, with a primary deficiency of parallel fiber to Purkinje cell synapse, short- and long-term fear memories are affected. All these data support the idea that the cerebellum participates in fear learning. The functional interconnection of the vermis with hypothalamus, amygdala, and hippocampus suggests a more complex role of the cerebellum as part of an integrated network regulating emotional behavior.
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Affiliation(s)
- Benedetto Sacchetti
- Rita Levi-Montalcini Center for Brain Repair, Department of Neuroscience, University of Turin, Turin, Italy
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Dadak S, Bouquier N, Goyet E, Fagni L, Levenes C, Perroy J. mGlu1 receptor canonical signaling pathway contributes to the opening of the orphan GluD2 receptor. Neuropharmacology 2016; 115:92-99. [PMID: 27276689 DOI: 10.1016/j.neuropharm.2016.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 05/19/2016] [Accepted: 06/02/2016] [Indexed: 11/18/2022]
Abstract
The orphan Glutamate receptor Delta2 (GluD2) intrinsic ion channel activity is indirectly triggered by glutamate through stimulation of the metabotropic glutamate receptor 1 (mGlu1), in cerebellar Purkinje cells. However, the mechanisms of GluD2 ion channel opening are entirely unknown. In this work, we investigated the signaling pathways underlying the mGlu1-induced GluD2 current, performing whole-cell voltage-clamp recordings from mGlu1 and GluD2 transfected HEK293 cells. We show that the activation of GluD2 channels via DHPG-induced mGlu1 stimulation is Gαq-dependent. Moreover, inhibition of the downstream components of the mGlu1 canonical signaling pathway PLC and PKC with U73122 and GF109203X, respectively, strongly reduced the DHPG-induced GluD2 current. These results were further confirmed on endogenous receptors at the Parallel Fiber - Purkinje Cell cerebellar synapse, indicating that the opening of the GluD2 channel by mGlu1 receptor mobilizes the canonical Gq-PLC-PKC pathway. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Selma Dadak
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France; INSERM, U1191, Montpellier, F-34094, France; Université de Montpellier, UMR-5203, Montpellier, F-34094, France
| | - Nathalie Bouquier
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France; INSERM, U1191, Montpellier, F-34094, France; Université de Montpellier, UMR-5203, Montpellier, F-34094, France
| | - Elise Goyet
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France; INSERM, U1191, Montpellier, F-34094, France; Université de Montpellier, UMR-5203, Montpellier, F-34094, France
| | - Laurent Fagni
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France; INSERM, U1191, Montpellier, F-34094, France; Université de Montpellier, UMR-5203, Montpellier, F-34094, France
| | - Carole Levenes
- CNRS, UMR 8119 Neurophysics and Physiology Laboratory, Université Paris Descartes, Paris, France
| | - Julie Perroy
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France; INSERM, U1191, Montpellier, F-34094, France; Université de Montpellier, UMR-5203, Montpellier, F-34094, France.
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Kristensen AS, Hansen KB, Naur P, Olsen L, Kurtkaya NL, Dravid SM, Kvist T, Yi F, Pøhlsgaard J, Clausen RP, Gajhede M, Kastrup JS, Traynelis SF. Pharmacology and Structural Analysis of Ligand Binding to the Orthosteric Site of Glutamate-Like GluD2 Receptors. Mol Pharmacol 2015; 89:253-62. [PMID: 26661043 DOI: 10.1124/mol.115.100909] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/07/2015] [Indexed: 11/22/2022] Open
Abstract
The GluD2 receptor is a fundamental component of postsynaptic sites in Purkinje neurons, and is required for normal cerebellar function. GluD2 and the closely related GluD1 are classified as members of the ionotropic glutamate receptor (iGluR) superfamily on the basis of sequence similarity, but do not bind l-glutamate. The amino acid neurotransmitter D-Ser is a GluD2 receptor ligand, and endogenous D-Ser signaling through GluD2 has recently been shown to regulate endocytosis of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type iGluRs during synaptic plasticity in the cerebellum, such as long-term depression. Here, we investigate the pharmacology of the orthosteric binding site in GluD2 by examining the activity of analogs of D-Ser and GluN1 glycine site competitive antagonists at GluD2 receptors containing the lurcher mutation (GluD2(LC)), which promotes spontaneous channel activation. We identify several compounds that modulate GluD2(LC), including a halogenated alanine analog as well as the kynurenic acid analog 7-chloro-4-oxo-1H-quinoline-2-carboxylic acid (7-chlorokynurenic acid; 7-CKA). By correlating thermodynamic and structural data for 7-CKA binding to the isolated GluD2 ligand binding domain (GluD2-LBD), we find that binding 7-CKA to GluD2-LBD differs from D-Ser by inducing an intermediate cleft closure of the clamshell-shaped LBD. The GluD2 ligands identified here can potentially serve as a starting point for development of GluD2-selective ligands useful as tools in studies of the signaling role of the GluD2 receptor in the brain.
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Affiliation(s)
- Anders S Kristensen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Kasper B Hansen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Peter Naur
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Lars Olsen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Natalie L Kurtkaya
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Shashank M Dravid
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Trine Kvist
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Feng Yi
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Jacob Pøhlsgaard
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Rasmus P Clausen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Michael Gajhede
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Jette S Kastrup
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (A.S.K., K.B.H., N.L.K., S.M.D., S.F.T.); Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark (A.S.K., P.N., L.O., T.K., J.P., R.P.C., M.G., J.S.K.); and Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana (K.B.H., F.Y.)
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18
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Dawe GB, Aurousseau MR, Daniels BA, Bowie D. Retour aux sources: defining the structural basis of glutamate receptor activation. J Physiol 2015; 593:97-110. [PMID: 25556791 PMCID: PMC4293057 DOI: 10.1113/jphysiol.2014.277921] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/05/2014] [Indexed: 01/12/2023] Open
Abstract
Ionotropic glutamate receptors (iGluRs) are the major excitatory neurotransmitter receptor in the vertebrate CNS and, as a result, their activation properties lie at the heart of much of the neuronal network activity observed in the developing and adult brain. iGluRs have also been implicated in many nervous system disorders associated with postnatal development (e.g. autism, schizophrenia), cerebral insult (e.g. stroke, epilepsy), and disorders of the ageing brain (e.g. Alzheimer's disease, Parkinsonism). In view of this, an emphasis has been placed on understanding how iGluRs activate and desensitize in functional and structural terms. Early structural models of iGluRs suggested that the strength of the agonist response was primarily governed by the degree of closure induced in the ligand-binding domain (LBD). However, recent studies have suggested a more nuanced role for the LBD with current evidence identifying the iGluR LBD interface as a "hotspot" regulating agonist behaviour. Such ideas remain to be consolidated with recently solved structures of full-length iGluRs to account for the global changes that underlie channel activation and desensitization.
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Affiliation(s)
- G Brent Dawe
- Integrated Program in Neuroscience, McGill UniversityMontréal, Québec, Canada
- Department of Pharmacology and Therapeutics, McGill UniversityMontréal, Québec, Canada
| | - Mark R Aurousseau
- Graduate Program in Pharmacology, McGill UniversityMontréal, Québec, Canada
- Department of Pharmacology and Therapeutics, McGill UniversityMontréal, Québec, Canada
| | - Bryan A Daniels
- Department of Pharmacology and Therapeutics, McGill UniversityMontréal, Québec, Canada
| | - Derek Bowie
- Department of Pharmacology and Therapeutics, McGill UniversityMontréal, Québec, Canada
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19
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: ligand-gated ion channels. Br J Pharmacol 2014; 170:1582-606. [PMID: 24528238 PMCID: PMC3892288 DOI: 10.1111/bph.12446] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. Ligand-gated ion channels are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen P H Alexander
- School of Life Sciences, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
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20
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Kohda K, Kakegawa W, Yuzaki M. Unlocking the secrets of the δ2 glutamate receptor: A gatekeeper for synaptic plasticity in the cerebellum. Commun Integr Biol 2013; 6:e26466. [PMID: 24563706 PMCID: PMC3916355 DOI: 10.4161/cib.26466] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 09/12/2013] [Indexed: 11/19/2022] Open
Abstract
Long-term changes in synaptic transmission in the central nervous system, such as long-term potentiation and long-term depression (LTD), are believed to underlie learning and memory in vivo. Despite intensive research, the precise molecular mechanisms underlying these phenomena have remained unclear. LTD is most commonly caused by the endocytosis of postsynaptic AMPA-type glutamate receptors, triggered by activity-induced serine phosphorylation of the GluA2 subunit. Interestingly, cerebellar LTD, which occurs at synapses between parallel fibers (PFs; axons of granule cells) and Purkinje cells, is unique in requiring an additional type of glutamate receptor, the δ2 receptor (GluD2). Cbln1 was recently identified as a GluD2 ligand that regulates PF synapse formation and maintenance. However, how GluD2 induces downstream signaling in Purkinje cells to regulate LTD induction is unknown. We here present evidence that GluD2 reduces the tyrosine phosphorylation level of the GluA2 subunit via PTPMEG, a protein tyrosine phosphatase that binds to GluD2's C-terminus. We also found that the serine phosphorylation of GluA2, a crucial step for AMPA-receptor endocytosis, requires prior tyrosine dephosphorylation. Thus, GluD2 may serve as a gatekeeper for LTD induction by coordinating interactions between GluA2's 2 phosphorylation sites.
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Affiliation(s)
- Kazuhisa Kohda
- Department of Physiology; Keio University School of Medicine; Tokyo, Japan
| | - Wataru Kakegawa
- Department of Physiology; Keio University School of Medicine; Tokyo, Japan
| | - Michisuke Yuzaki
- Department of Physiology; Keio University School of Medicine; Tokyo, Japan
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21
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Pregno G, Frola E, Graziano S, Patrizi A, Bussolino F, Arese M, Sassoè-Pognetto M. Differential regulation of neurexin at glutamatergic and GABAergic synapses. Front Cell Neurosci 2013; 7:35. [PMID: 23576952 PMCID: PMC3616244 DOI: 10.3389/fncel.2013.00035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/18/2013] [Indexed: 11/30/2022] Open
Abstract
Neurexins (Nrxs) have emerged as potential determinants of synaptic specificity, but little is known about their localization at central synapses. Here we show that Nrxs have a remarkably selective localization at distinct types of glutamatergic synapses and we reveal an unexpected ontogenetic regulation of Nrx expression at GABAergic synapses. Our data indicate that synapses are specified by molecular interactions that involve both Nrx-dependent and Nrx-independent mechanisms. We propose that differences in the spatio-temporal profile of Nrx expression may contribute to specify the molecular identity of synapses.
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Affiliation(s)
- Giulia Pregno
- Department of Neuroscience, University of Turin Torino, Italy
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22
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Matsuda K, Yuzaki M. Cbln1 and the δ2 glutamate receptor--an orphan ligand and an orphan receptor find their partners. THE CEREBELLUM 2012; 11:78-84. [PMID: 20535596 DOI: 10.1007/s12311-010-0186-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cerebellin was originally discovered as a Purkinje cell-specific peptide more than two decades ago. Later, its precursor protein precerebellin (Cbln1) was found to be produced in cerebellar granule cells. It has become increasingly clear that although the cerebellin peptide may have certain functions, Cbln1 is an actual signaling molecule that belongs to the C1q family. However, the precise function of Cbln1 has been unresolved. Cbln1 is released from granule cells, and disruption of the cbln1 gene in mice causes a severe reduction in the number of synapses between Purkinje cells and parallel fibers (PFs; axons of granule cells) and results in cerebellar ataxia. The glutamate receptor δ2 (GluD2) is highly expressed on Purkinje cells' dendritic spines which make synapses with PFs. Although GluD2 was identified as a member of the ionotropic glutamate receptors more than 15 years ago, it has been referred to as an orphan receptor because its endogenous ligands are unclear. Interestingly, GluD2-null mice phenocopy cbln1-null mice precisely. Cbln1 and GluD2 have therefore been thought to participate in a common signaling pathway that is required for the formation of PF synapses. We recently established a direct ligand-receptor relationship between Cbln1 and GluD2. The Cbln1-GluD2 complex is located at the cleft of PF-Purkinje cell synapses and bidirectionally regulates both presynaptic and postsynaptic differentiation.
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Affiliation(s)
- Keiko Matsuda
- Department of Neurophysiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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23
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Abel JL, Rissman EF. Running-induced epigenetic and gene expression changes in the adolescent brain. Int J Dev Neurosci 2012. [PMID: 23178748 DOI: 10.1016/j.ijdevneu.2012.11.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Physical exercise is associated with positive neural functioning. Here we examined the gene expression consequences of 1 week of voluntary wheel running in adolescent male mice. We assayed expression levels of genes associated with synaptic plasticity, signaling pathways, and epigenetic modifying enzymes. Two regions were examined: the hippocampus, which is typically examined in exercise studies, and the cerebellum, an area directly involved in motor control and learning. After 1 week of exercise, global acetylation of histone 3 was increased in both brain regions. Interestingly this was correlated with increased brain derived neural growth factor in the hippocampus, as noted in many other studies, but only a trend was found in cerebellum. Differences and similarities between the two areas were noted for genes encoding functional proteins. In contrast, the expression pattern of DNA methyltransferases (Dnmts) and histone deacetylases (Hdacs), genes that influence DNA methylation and histone modifications in general, decreased in both regions with exercise. We hypothesize that epigenetic mechanisms, involving many of the genes assessed here, are essential for the positive affects of exercise on behavior and suspect these data have relevance for adolescent boys.
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Affiliation(s)
- Jean LeBeau Abel
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, United States
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24
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Yuzaki M. The ins and outs of GluD2--why and how Purkinje cells use the special glutamate receptor. THE CEREBELLUM 2012; 11:438-9. [PMID: 22113500 DOI: 10.1007/s12311-011-0328-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
The δ2 glutamate receptor (GluD2) is predominantly expressed in cerebellar Purkinje cells and plays crucial roles in cerebellar functions. Indeed, the number of synapses between parallel fibers (PFs) and Purkinje cells is specifically and severely reduced in GluD2-null cerebellum. In addition, long-term depression (LTD) at PF-Purkinje cell synapses is impaired in these mice. Nevertheless, the mechanism by which GluD2 regulate these two functions-morphological and functional synaptic plasticity at PF synapses-has remained unclear. Recently, we found that Cbln1, a glycoprotein released from granule cells, was bound to the N-terminal domain of GluD2 and regulated formation and maintenance of PF-Purkinje cell synapses. Furthermore, we found that D: -Ser released from Bergmann glia bound the ligand-binding domain of GluD2 and mediated LTD in a manner dependent on the C-terminus. These findings indicate how GluD2 is activated and regulates functions at PF-Purkinje cell synapses. A hypothesis about why GluD2 is employed by PF synapses is also discussed.
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Affiliation(s)
- Michisuke Yuzaki
- School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan.
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25
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Lemoine D, Jiang R, Taly A, Chataigneau T, Specht A, Grutter T. Ligand-gated ion channels: new insights into neurological disorders and ligand recognition. Chem Rev 2012; 112:6285-318. [PMID: 22988962 DOI: 10.1021/cr3000829] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Damien Lemoine
- Laboratoire de Biophysicochimie des Récepteurs Canaux, UMR 7199 CNRS, Conception et Application de Molécules Bioactives, Faculté de Pharmacie, Université de Strasbourg , 67400 Illkirch, France
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26
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Armstrong CL, Duffin CA, McFarland R, Vogel MW. Mechanisms of compartmental purkinje cell death and survival in the lurcher mutant mouse. THE CEREBELLUM 2012; 10:504-14. [PMID: 21104177 DOI: 10.1007/s12311-010-0231-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Lurcher mutant mouse is characterized by its ataxic gait and loss of cerebellar Purkinje cells and their afferents, granule cells and olivary neurons, during the first weeks of postnatal development. For the 50 years since its discovery, the heterozygous Lurcher mutant has served as an important model system for studying neuron-target interactions in the developing cerebellum and cerebellar function. The identification of the Lurcher (Lc) gene over 10 years ago as a gain-of-function mutation in the δ2 glutamate receptor (GluRδ2) led to extensive studies of cell death mechanisms in the Lc/+ cerebellum. The advantage of this model system is that GluRδ2(+) receptors and GluRδ2(Lc) channels are expressed predominantly in Purkinje cells, making it possible to study the effects of a well-characterized leak current in a well-defined cell type during a critical phase of neuronal development. Yet there is still controversy surrounding the mechanisms of neuronal death in Lc/+ Purkinje cells with competing hypotheses for necrotic, apoptotic, and autophagic cell death pathways as a consequence of the excitotoxic stress caused by the GluRδ2(Lc) leak current. The goal of this review is to summarize recent studies that critically test the role of various cell death pathways in Lc/+ Purkinje cell degeneration with respect to evidence for the molecular heterogeneity of Purkinje cells. We propose that the expression of putative survival factors, such as heat shock proteins, in a subset of cerebellar Purkinje cells may affect cell death pathways and account for the pattern and diverse mechanisms of Lc/+ Purkinje degeneration.
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Affiliation(s)
- Carol L Armstrong
- Department of Chemical and Biological Sciences, Mt Royal University, Calgary, AB, Canada, T3E 6K6
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27
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Cesa R, Premoselli F, Renna A, Ethell IM, Pasquale EB, Strata P. Eph receptors are involved in the activity-dependent synaptic wiring in the mouse cerebellar cortex. PLoS One 2011; 6:e19160. [PMID: 21559471 PMCID: PMC3084771 DOI: 10.1371/journal.pone.0019160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 03/25/2011] [Indexed: 11/19/2022] Open
Abstract
Eph receptor tyrosine kinases are involved in many cellular processes. In the developing brain, they act as migratory and cell adhesive cues while in the adult brain they regulate dendritic spine plasticity. Here we show a new role for Eph receptor signalling in the cerebellar cortex. Cerebellar Purkinje cells are innervated by two different excitatory inputs. The climbing fibres contact the proximal dendritic domain of Purkinje cells, where synapse and spine density is low; the parallel fibres contact the distal dendritic domain, where synapse and spine density is high. Interestingly, Purkinje cells have the intrinsic ability to generate a high number of spines over their entire dendritic arborisations, which can be innervated by the parallel fibres. However, the climbing fibre input continuously exerts an activity-dependent repression on parallel fibre synapses, thus confining them to the distal Purkinje cell dendritic domain. Such repression persists after Eph receptor activation, but is overridden by Eph receptor inhibition with EphA4/Fc in neonatal cultured cerebellar slices as well as mature acute cerebellar slices, following in vivo infusion of the EphA4/Fc inhibitor and in EphB receptor-deficient mice. When electrical activity is blocked in vivo by tetrodotoxin leading to a high spine density in Purkinje cell proximal dendrites, stimulation of Eph receptor activation recapitulates the spine repressive effects of climbing fibres. These results suggest that Eph receptor signalling mediates the repression of spine proliferation induced by climbing fibre activity in Purkinje cell proximal dendrites. Such repression is necessary to maintain the correct architecture of the cerebellar cortex.
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Affiliation(s)
- Roberta Cesa
- Department of Neuroscience, University of Turin, Turin, Italy
- National Neuroscience Institute-Italy at Turin University, Turin, Italy
| | | | - Annamaria Renna
- Department of Neuroscience, University of Turin, Turin, Italy
- National Neuroscience Institute-Italy at Turin University, Turin, Italy
| | - Iryna M. Ethell
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, United States of America
| | - Elena B. Pasquale
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Piergiorgio Strata
- National Neuroscience Institute-Italy at Turin University, Turin, Italy
- * E-mail:
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28
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Gómez-Nieto R, Rubio ME. Ultrastructure, synaptic organization, and molecular components of bushy cell networks in the anteroventral cochlear nucleus of the rhesus monkey. Neuroscience 2011; 179:188-207. [PMID: 21284951 DOI: 10.1016/j.neuroscience.2011.01.058] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 01/22/2011] [Accepted: 01/24/2011] [Indexed: 11/28/2022]
Abstract
Bushy cells (BCs) process auditory information in the ventral cochlear nucleus (VCN). Yet, most neuroanatomical findings come from studies in cats and rodents, and the ultrastructural morphological features of BCs in humans and higher nonhuman primates are unknown. In this study, we combined histological, immunocytochemical, and ultrastructural methods to examine the morphology and synaptic organization of BCs in the rhesus monkey VCN. We observed that BCs were organized in a complex neural network that appears to interconnect the cells. The fine structure of BC somata and dendrites, as well as their synaptic inputs, are similar to those in other mammals. We found that BCs received numerous endbulb-like VGLUT1- and VGLUT2-immunopositive endings. In addition, they expressed glutamate AMPA (GluR2/3 and GluR4), NMDA (NR1), delta1/2 receptor subunits, and the α1 subunit of the glycine receptor. These receptor types and subunits mediate fast excitatory synaptic transmission from the cochlea and inhibitory neurotransmission from noncochlear inputs. Parvalbumin immunostaining and semithin sections showed that BC dendrites are oriented toward neighboring BC somas to form neuronal clusters. Within the cluster, the incoming inputs established multiple, divergent synaptic contacts. Thus, BCs were connected by specialized dendrosomatic and somasomatic membrane junctions. Our results indicate that the cytoarchitectural organization of BCs is well conserved between primates and other mammalian species.
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Affiliation(s)
- R Gómez-Nieto
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, Storrs, CT 06269-3156, USA
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29
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Abstract
The assembly of specific synaptic connections during development of the nervous system represents a remarkable example of cellular recognition and differentiation. Neurons employ several different cellular signaling strategies to solve this puzzle, which successively limit unwanted interactions and reduce the number of direct recognition events that are required to result in a specific connectivity pattern. Specificity mechanisms include the action of contact-mediated and long-range signals that support or inhibit synapse formation, which can take place directly between synaptic partners or with transient partners and transient cell populations. The molecular signals that drive the synaptic differentiation process at individual synapses in the central nervous system are similarly diverse and act through multiple, parallel differentiation pathways. This molecular complexity balances the need for central circuits to be assembled with high accuracy during development while retaining plasticity for local and dynamic regulation.
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Affiliation(s)
- Kang Shen
- Howard Hughes Medical Institute, Department of Biology and Pathology, Stanford University, Stanford, California 94305, USA.
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Yadav R, Rimerman R, Scofield MA, Dravid SM. Mutations in the transmembrane domain M3 generate spontaneously open orphan glutamate δ1 receptor. Brain Res 2011; 1382:1-8. [PMID: 21215726 DOI: 10.1016/j.brainres.2010.12.086] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 12/28/2010] [Accepted: 12/30/2010] [Indexed: 12/22/2022]
Abstract
Glutamate delta-1 receptors (GluRδ1) are expressed in the adult hippocampus and inner ear and have recently been shown to be important for high-frequency hearing. Similar to the closest homolog glutamate delta-2 receptor (GluRδ2), no agonist-induced currents are observed from GluRδ1 receptors. In an effort to understand the function of the GluRδ1 subunit, we probed the conserved transmembrane 3 (TM3) region of the GluRδ1 subunit, where the GluRδ2 lurcher mutation is localized. Four mutations in the TM3 domain A650C, L652A, A654C, and F655A resulted in spontaneously open GluRδ1 channels suggesting that GluRδ1 receptors can form homomeric receptors. The leak currents were partially blocked by pentamidine but showed negligible inhibition by NASP. It has been demonstrated that extracellular Ca(2+) binds and stabilizes the ligand binding domain (LBD) dimer interface leading to potentiation of currents through GluRδ2(Lc) channels. We found that extracellular Ca(2+) potentiated the spontaneous currents through GluRδ1F655A suggesting that extracellular Ca(2+) may interact with the conserved residues at GluRδ1 LBD dimer interface. A recent study suggested that d-serine and glycine bind to the GluRδ2 LBD and reduce spontaneous currents through the GluRδ2(Lc) channels. d-Serine and glycine produced only a modest reduction of spontaneous currents through GluRδ1F655A and had no effect on the spontaneous current through GluRδ1L652A. However, spontaneous currents in a chimeric GluRδ1-δ2(Lc) were robustly inhibited by d-serine. These results suggest that the activation gate is conserved in GluRδ1 receptors. Moreover, the conformational changes induced by d-serine and extracellular Ca(2+) are conserved among GluRδ1 and GluRδ2 receptors.
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Affiliation(s)
- Roopali Yadav
- Department of Pharmacology, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
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31
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Yuzaki M. Synapse formation and maintenance by C1q family proteins: a new class of secreted synapse organizers. Eur J Neurosci 2010; 32:191-7. [PMID: 20646056 DOI: 10.1111/j.1460-9568.2010.07346.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Several C1q family members, especially the Cbln and C1q-like subfamilies, are highly and predominantly expressed in the central nervous system. Cbln1, a member of the Cbln subfamily, plays two unique roles at parallel fiber (PF)-Purkinje cell synapses in the cerebellum: the formation and stabilization of synaptic contact, and the control of functional synaptic plasticity by regulating the postsynaptic endocytotic pathway. The delta2 glutamate receptor (GluD2), which is predominantly expressed in Purkinje cells, plays similar critical roles in the cerebellum. In addition, viral expression of GluD2 or the application of recombinant Cbln1 induces PF-Purkinje cell synaptogenesis in vitro and in vivo. Antigen-unmasking methods were necessary to reveal the immunoreactivities for endogenous Cbln1 and GluD2 at the synaptic junction of PF synapses. We propose that Cbln1 and GluD2 are located at the synaptic cleft, where various proteins undergo intricate molecular interactions with each other, and serve as a bidirectional synaptic organizer.
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Affiliation(s)
- Michisuke Yuzaki
- Department of Physiology, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
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32
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Boele HJ, Koekkoek SKE, De Zeeuw CI. Cerebellar and extracerebellar involvement in mouse eyeblink conditioning: the ACDC model. Front Cell Neurosci 2010; 3:19. [PMID: 20126519 PMCID: PMC2805432 DOI: 10.3389/neuro.03.019.2009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 11/29/2009] [Indexed: 11/20/2022] Open
Abstract
Over the past decade the advent of mouse transgenics has generated new perspectives on the study of cerebellar molecular mechanisms that are essential for eyeblink conditioning. However, it also appears that results from eyeblink conditioning experiments done in mice differ in some aspects from results previously obtained in other mammals. In this review article we will, based on studies using (cell-specific) mouse mutants and region-specific lesions, re-examine the general eyeblink behavior in mice and the neuro-anatomical circuits that might contribute to the different peaks in the conditioned eyeblink trace. We conclude that the learning process in mice has at least two stages: An early stage, which includes short-latency responses that are at least partly controlled by extracerebellar structures such as the amygdala, and a later stage, which is represented by well-timed conditioned responses that are mainly controlled by the pontocerebellar and olivocerebellar systems. We refer to this overall concept as the Amygdala-Cerebellum-Dynamic-Conditioning Model (ACDC model).
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Affiliation(s)
- Henk-Jan Boele
- Department of Neuroscience, Erasmus Medical Center, RotterdamThe Netherlands
| | | | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus Medical Center, RotterdamThe Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, AmsterdamThe Netherlands
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Proteomic studies of a single CNS synapse type: the parallel fiber/purkinje cell synapse. PLoS Biol 2009; 7:e83. [PMID: 19402746 PMCID: PMC2672601 DOI: 10.1371/journal.pbio.1000083] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 03/02/2009] [Indexed: 01/04/2023] Open
Abstract
Precise neuronal networks underlie normal brain function and require distinct classes of synaptic connections. Although it has been shown that certain individual proteins can localize to different classes of synapses, the biochemical composition of specific synapse types is not known. Here, we have used a combination of genetically engineered mice, affinity purification, and mass spectrometry to profile proteins at parallel fiber/Purkinje cell synapses. We identify approximately 60 candidate postsynaptic proteins that can be classified into 11 functional categories. Proteins involved in phospholipid metabolism and signaling, such as the protein kinase MRCKgamma, are major unrecognized components of this synapse type. We demonstrate that MRCKgamma can modulate maturation of dendritic spines in cultured cortical neurons, and that it is localized specifically to parallel fiber/Purkinje cell synapses in vivo. Our data identify a novel synapse-specific signaling pathway, and provide an approach for detailed investigations of the biochemical complexity of central nervous system synapse types.
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Verkerk AJMH, Schot R, Dumee B, Schellekens K, Swagemakers S, Bertoli-Avella AM, Lequin MH, Dudink J, Govaert P, van Zwol AL, Hirst J, Wessels MW, Catsman-Berrevoets C, Verheijen FW, de Graaff E, de Coo IFM, Kros JM, Willemsen R, Willems PJ, van der Spek PJ, Mancini GMS. Mutation in the AP4M1 gene provides a model for neuroaxonal injury in cerebral palsy. Am J Hum Genet 2009; 85:40-52. [PMID: 19559397 DOI: 10.1016/j.ajhg.2009.06.004] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 05/28/2009] [Accepted: 06/10/2009] [Indexed: 12/14/2022] Open
Abstract
Cerebral palsy due to perinatal injury to cerebral white matter is usually not caused by genetic mutations, but by ischemia and/or inflammation. Here, we describe an autosomal-recessive type of tetraplegic cerebral palsy with mental retardation, reduction of cerebral white matter, and atrophy of the cerebellum in an inbred sibship. The phenotype was recorded and evolution followed for over 20 years. Brain lesions were studied by diffusion tensor MR tractography. Homozygosity mapping with SNPs was performed for identification of the chromosomal locus for the disease. In the 14 Mb candidate region on chromosome 7q22, RNA expression profiling was used for selecting among the 203 genes in the area. In postmortem brain tissue available from one patient, histology and immunohistochemistry were performed. Disease course and imaging were mostly reminiscent of hypoxic-ischemic tetraplegic cerebral palsy, with neuroaxonal degeneration and white matter loss. In all five patients, a donor splice site pathogenic mutation in intron 14 of the AP4M1 gene (c.1137+1G-->T), was identified. AP4M1, encoding for the mu subunit of the adaptor protein complex-4, is involved in intracellular trafficking of glutamate receptors. Aberrant GluRdelta2 glutamate receptor localization and dendritic spine morphology were observed in the postmortem brain specimen. This disease entity, which we refer to as congenital spastic tetraplegia (CST), is therefore a genetic model for congenital cerebral palsy with evidence for neuroaxonal damage and glutamate receptor abnormality, mimicking perinatally acquired hypoxic-ischemic white matter injury.
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The N-terminal domain of GluD2 (GluRdelta2) recruits presynaptic terminals and regulates synaptogenesis in the cerebellum in vivo. J Neurosci 2009; 29:5738-48. [PMID: 19420242 DOI: 10.1523/jneurosci.6013-08.2009] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The delta2 glutamate receptor (GluRdelta2; GluD2), which is predominantly expressed on postsynaptic sites at parallel fiber (PF)-Purkinje cell synapses in the cerebellum, plays two crucial roles in the cerebellum: the formation of PF synapses and the regulation of long-term depression (LTD), a form of synaptic plasticity underlying motor learning. Although the induction of LTD and motor learning absolutely require signaling via the cytoplasmic C-terminal domain of GluD2, the mechanisms by which GluD2 regulates PF synaptogenesis have remained unclear. Here, we examined the role of the extracellular N-terminal domain (NTD) of GluD2 on PF synaptogenesis by injecting Sindbis virus carrying wild-type (GluD2(wt)) or mutant GluD2 into the subarachnoid supracerebellar space of GluD2-null mice. Remarkably, the expression of GluD2(wt), but not of a mutant GluD2 lacking the NTD (GluD2(DeltaNTD)), rapidly induced PF synapse formation and rescued gross motor dyscoordination in adult GluD2-null mice just 1 d after injection. In addition, although the kainate receptor GluR6 (GluK2) did not induce PF synaptogenesis, a chimeric GluK2 that contained the NTD of GluD2 (GluD2(NTD)-GluK2) did. Similarly, GluD2(wt) and GluD2(NTD)-GluK2, but not GluD2(DeltaNTD), induced synaptogenesis in heterologous cells in vitro. In contrast, LTD was restored in GluD2-null Purkinje cells expressing a mutant GluD2 lacking the NTD. These results indicate that the NTD of GluD2 is necessary and sufficient for the function of GluD2 in the regulation of PF-Purkinje cell synaptogenesis. Furthermore, our results suggest that GluD2 differently regulates PF synaptogenesis and cerebellar LTD through the extracellular NTD and the cytoplasmic C-terminal end, respectively.
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Mandolesi G, Autuori E, Cesa R, Premoselli F, Cesare P, Strata P. GluRdelta2 expression in the mature cerebellum of hotfoot mice promotes parallel fiber synaptogenesis and axonal competition. PLoS One 2009; 4:e5243. [PMID: 19370152 PMCID: PMC2666267 DOI: 10.1371/journal.pone.0005243] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 03/19/2009] [Indexed: 12/02/2022] Open
Abstract
Glutamate receptor delta 2 (GluRdelta2) is selectively expressed in the cerebellum, exclusively in the spines of the Purkinje cells (PCs) that are in contact with parallel fibers (PFs). Although its structure is similar to ionotropic glutamate receptors, it has no channel function and its ligand is unknown. The GluRdelta2-null mice, such as knockout and hotfoot have profoundly altered cerebellar circuitry, which causes ataxia and impaired motor learning. Notably, GluRdelta2 in PC-PF synapses regulates their maturation and strengthening and induces long term depression (LTD). In addition, GluRdelta2 participates in the highly territorial competition between the two excitatory inputs to the PC; the climbing fiber (CF), which innervates the proximal dendritic compartment, and the PF, which is connected to spiny distal branchlets. Recently, studies have suggested that GluRdelta2 acts as an adhesion molecule in PF synaptogenesis. Here, we provide in vivo and in vitro evidence that supports this hypothesis. Through lentiviral rescue in hotfoot mice, we noted a recovery of PC-PF contacts in the distal dendritic domain. In the proximal domain, we observed the formation of new spines that were innervated by PFs and a reduction in contact with the CF; ie, the pattern of innervation in the PC shifted to favor the PF input. Moreover, ectopic expression of GluRdelta2 in HEK293 cells that were cocultured with granule cells or in cerebellar Golgi cells in the mature brain induced the formation of new PF contacts. Collectively, our observations show that GluRdelta2 is an adhesion molecule that induces the formation of PF contacts independently of its cellular localization and promotes heterosynaptic competition in the PC proximal dendritic domain.
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37
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Janmaat S, Frédéric F, Sjollema K, Luiten P, Mariani J, van der Want J. Formation and maturation of parallel fiber-Purkinje cell synapses in the Staggerer cerebellum ex vivo. J Comp Neurol 2009; 512:467-77. [PMID: 19025990 DOI: 10.1002/cne.21910] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In vivo, homozygous staggerer (Rora(sg/sg)) Purkinje cells (PCs) remain in an early stage of development with rudimentary spineless dendrites, associated with a lack of parallel fiber (PF) input and the persistence of multiple climbing fibers (CFs). In this immunocytochemical study we used cerebellar organotypic cultures to monitor the development of Rora(sg/sg) PF-PC synapses in the absence of CF innervation. Ex vivo the vesicular glutamate transporters VGluT1 and VGluT2 reactivity was preferentially localized around the Rora(sg/sg) PC soma and proximal dendrites, which are typically CF domains. The shift from VGluT2 to VGluT1 in PF terminals during development was delayed in Rora(sg/sg) slices. The postsynaptic receptors mGluR1 and GluRdelta2 were differently distributed on Rora(sg/sg) PCs. mGluR1 reactivity was evenly distributed in PC soma and dendrites, whereas GluRdelta2 reactivity, normally restricted at PF synapses, was dense in Rora(sg/sg) PC somata. The presynaptic distribution of VGluT1 and VGluT2 on Rora(sg/sg) PCs matched the postsynaptic distribution of the glutamate receptor GluRdelta2, but not mGluR1.
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Affiliation(s)
- Sonja Janmaat
- Department of Cell Biology, Molecular Imaging and Electron Microscopy, University Medical Center Groningen, University of Groningen, The Netherlands
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38
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Sacchetti B, Scelfo B, Strata P. Cerebellum and emotional behavior. Neuroscience 2009; 162:756-62. [PMID: 19409218 DOI: 10.1016/j.neuroscience.2009.01.064] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/26/2009] [Accepted: 01/27/2009] [Indexed: 11/17/2022]
Abstract
Fear conditioning involves learning that a previously neutral stimulus (CS) predicts an aversive unconditioned stimulus (US). Lesions of the cerebellar vermis may affect fear memory without altering baseline motor/autonomic responses to the frightening stimuli. Reversible inactivation of the vermis during the consolidation period impairs retention of fear memory. In patients with medial cerebellar lesions conditioned bradycardia is impaired. In humans, cerebellar areas around the vermis are activated during mental recall of emotional personal episodes, if a loved partner receives a pain stimulus, and during learning of a CS-US association. Moreover, patients with cerebellar stroke may fail to show overt emotional changes. In such patients, however, the activity of several areas, including ventromedial prefrontal cortex, anterior cingulate, pulvinar and insular cortex, is significantly increased relative to healthy subjects when exposed to frightening stimuli. Therefore, other structures may serve to maintain fear response after cerebellar damage. These data indicate that the vermis is involved in the formation of fear memory traces. We suggest that the vermis is not only involved in regulating the autonomic/motor responses, but that it also participates in forming new CS-US associations thus eliciting appropriate responses to new stimuli or situations. In other words, the cerebellum may translate an emotional state elaborated elsewhere into autonomic and motor responses.
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Affiliation(s)
- B Sacchetti
- Department of Neuroscience and National Institute of Neuroscience-Italy, University of Turin, Corso Raffaello 30, 10125 Turin, Italy.
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39
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Matsuda K, Kondo T, Iijima T, Matsuda S, Watanabe M, Yuzaki M. Cbln1 binds to specific postsynaptic sites at parallel fiber-Purkinje cell synapses in the cerebellum. Eur J Neurosci 2009; 29:707-17. [DOI: 10.1111/j.1460-9568.2009.06639.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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40
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An orphan ionotropic glutamate receptor: The δ2 subunit. Neuroscience 2009; 158:67-77. [DOI: 10.1016/j.neuroscience.2008.02.050] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 02/13/2008] [Accepted: 02/22/2008] [Indexed: 11/24/2022]
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41
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Santos S, Carvalho A, Caldeira M, Duarte C. Regulation of AMPA receptors and synaptic plasticity. Neuroscience 2009; 158:105-25. [DOI: 10.1016/j.neuroscience.2008.02.037] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 01/02/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
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42
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Hashimoto K, Yoshida T, Sakimura K, Mishina M, Watanabe M, Kano M. Influence of parallel fiber-Purkinje cell synapse formation on postnatal development of climbing fiber-Purkinje cell synapses in the cerebellum. Neuroscience 2008; 162:601-11. [PMID: 19166909 DOI: 10.1016/j.neuroscience.2008.12.037] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 12/08/2008] [Accepted: 12/24/2008] [Indexed: 11/29/2022]
Abstract
The climbing fiber (CF) to Purkinje cell (PC) synapse in the cerebellum provides an ideal model for the study of developmental rearrangements of neural circuits. At birth, each PC is innervated by multiple CFs. These surplus CFs are eliminated during postnatal development, and mono innervation is attained by postnatal day 20 (P20) in mice. Earlier studies on spontaneous mutant mice and animals with "hypogranular" cerebella indicate that regression of surplus CFs requires normal generation of granule cells and their axons, parallel fibers (PFs), and normal formation of PF-PC synapses. Our understanding of how PF-PC synapse formation affects development of CF-PC synapse has been greatly advanced by analyses of mutant mice deficient in glutamate receptor delta2 subunit (GluRdelta2), an orphan receptor expressed selectively in PCs. Deletion of GluRdelta2 results in impairment of PF-PC synapse formation, which leads to defects in development of CF-PC synapses. In this article, we review how impaired PF-PC synapse formation affects wiring of CFs to PCs based mostly on our data on GluRdelta2 knockout mice. We propose a new scheme that CF-PC synapses are shaped by the three consecutive events, namely functional differentiation of multiple CFs into one strong and a few weak inputs from P3 to P7, "early phase" of CF synapse elimination from P7 to around P11, and "late phase" of CF synapse elimination from around P12. Normal PF-PC synapse formation is required for the "late phase" of CF synapse elimination.
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Affiliation(s)
- K Hashimoto
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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43
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Yuzaki M. New (but old) molecules regulating synapse integrity and plasticity: Cbln1 and the delta2 glutamate receptor. Neuroscience 2008; 162:633-43. [PMID: 19124061 DOI: 10.1016/j.neuroscience.2008.12.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 12/01/2008] [Accepted: 12/03/2008] [Indexed: 11/28/2022]
Abstract
The delta2 glutamate receptor (GluRdelta2) is predominantly expressed in cerebellar Purkinje cells and plays crucial roles in cerebellar functions: GluRdelta2-null mice display ataxia and impaired motor learning. Interestingly, the contact state of synapses between parallel fibers (PFs) and Purkinje cells is specifically and severely affected, and the number of normal PF synapses is markedly reduced in GluRdelta2-null Purkinje cells. Furthermore, long-term depression at PF-Purkinje cell synapses is abrogated. Cbln1, a member of the C1q/tumor necrosis factor (TNF) superfamily, is predominantly expressed and released from cerebellar granule cells. Unexpectedly, the behavioral, physiological and anatomical phenotypes of cbln1-null mice precisely mimic those of GluRdelta2-null mice. Thus, we propose that Cbln1, which is released from granule cells, and GluRdelta2, which is predominantly expressed in Purkinje cells, are involved in a common signaling pathway crucial for synapse formation/maintenance and plasticity in the cerebellum. Since molecules related to Cbln1 are expressed in various brain regions other than the cerebellum, other C1q/TNF superfamily proteins may also regulate various aspects of synapses in the CNS. Therefore, an understanding of the signaling mechanisms underlying Cbln1 and GluRdelta2 in the cerebellum will provide new insights into the roles of C1q/TNF superfamily proteins as new cytokines that regulate normal and abnormal brain functions.
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Affiliation(s)
- M Yuzaki
- Department of Neurophysiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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44
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Bell CC, Han V, Sawtell NB. Cerebellum-Like Structures and Their Implications for Cerebellar Function. Annu Rev Neurosci 2008; 31:1-24. [DOI: 10.1146/annurev.neuro.30.051606.094225] [Citation(s) in RCA: 218] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Curtis C. Bell
- Neurological Sciences Institute, Oregon Health and Science University, Beaverton, Oregon 97006; ,
| | - Victor Han
- Oregon Regional Primate Center, Oregon Health and Science University, Beaverton, Oregon 97006;
| | - Nathaniel B. Sawtell
- Neurological Sciences Institute, Oregon Health and Science University, Beaverton, Oregon 97006; ,
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45
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Rubio ME, Gudsnuk KA, Smith Y, Ryugo DK. Revealing the molecular layer of the primate dorsal cochlear nucleus. Neuroscience 2008; 154:99-113. [PMID: 18222048 DOI: 10.1016/j.neuroscience.2007.12.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 11/30/2007] [Accepted: 12/02/2007] [Indexed: 11/18/2022]
Abstract
In nonprimate mammals, the dorsal cochlear nucleus (DCN) is thought to play a role in the orientation of the head toward sounds of interest by integrating acoustic and somatosensory information. Humans and higher primates might not use this system because of reported phylogenetic changes in DCN cytoarchitecture [Moskowitz N (1969) Comparative aspects of some features of the central auditory system of primates. Ann N Y Acad Sci 167:357-369; Moore JK, Osen KK (1979) The cochlear nuclei in man. Am J Anat 154:393-418; Moore JK (1980) The primate cochlear nuclei: loss of lamination as a phylogenetic process. J Comp Neurol 193:609-629]. In this study, we re-evaluated this question from a comparative perspective and examined the rhesus monkey (cercopithecoid primate) using more sensitive probes and higher resolution imaging methods. We used electron microscopy to identify parallel fibers and their synapses, and molecular markers to determine that primates exhibit the main components of excitatory neurotransmission as other mammals. We observed that characteristics of the monkey molecular layer resembled what has been reported for nonprimates: (1) immunohistochemistry revealed many unmyelinated, thin axons and en passant glutamatergic synapses on dendritic spines; (2) immunohistochemistry for phosphodiesterase (PDE10A) showed the nuclei of granule cells distributed in the external molecular layer and the deep layers in the DCN; (3) antibodies for the inositol trisphosphate receptor (IP3r) and calbindin immunostained cartwheel cells; (4) postembedding immunogold labeling revealed synaptic expression of AMPA and delta glutamate receptor subunits on spines in parallel fiber endings; and (5) parallel fibers use vesicular glutamate transporter 1 (VGLUT1) to package glutamate into the synaptic vesicles and to mediate glutamate transport. These observations are consistent with the argument that the rhesus monkey DCN has neuronal features similar to those of other nonprimate mammals.
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Affiliation(s)
- M E Rubio
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, Storrs, CT 06269-3156, USA.
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46
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Watanabe M. Molecular Mechanisms Governing Competitive Synaptic Wiring in Cerebellar Purkinje Cells. TOHOKU J EXP MED 2008; 214:175-90. [DOI: 10.1620/tjem.214.175] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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47
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Phosphorylation of Delta2 Glutamate Receptors at Serine 945 is Not Required for Cerebellar Long-term Depression. Keio J Med 2008; 57:105-10. [DOI: 10.2302/kjm.57.105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Cesa R, Strata P. Activity-dependent axonal and synaptic plasticity in the cerebellum. Psychoneuroendocrinology 2007; 32 Suppl 1:S31-5. [PMID: 17640822 DOI: 10.1016/j.psyneuen.2007.04.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 04/06/2007] [Indexed: 12/14/2022]
Abstract
The cerebellum is a brain region endowed with a high degree of plasticity also in adulthood. After damage or alteration in the patterns of activity, it is able to undergo remarkable changes in its architecture and to form new connections based upon a process of synaptic reorganization. This review addresses cellular and molecular mechanisms that regulate the competition between two inputs belonging to different neuronal populations in innervating two contiguous but separate domains of the same target cell. The two inputs are the parallel fibers, the axon of the cerebellar granule cells, and the olivocerebellar neurons, that terminate as climbing fibers in the cerebellar cortex. The target is the Purkinje cell characterized by two dendritic domains that are different in size and number of spines, upon which the two afferent inputs impinge. Both inputs express several genes related to plasticity throughout the life span conferring the ability to remodel their synapses. In addition, we provided evidence that climbing fibers and Purkinje cells show remarkable reciprocal trophic interactions that are required for the maintenance of the correct synaptic connectivity. Through their activity, climbing fibers sustain the competition with parallel fibers by displacing this input to the distal territory of the Purkinje cell dendrite. In addition, they operate on the Purkinje cells through AMPA receptor suppressing spines in the territory surrounding their synapses. In this way, climbing fibers are able to optimize spine distribution and functional connectivity.
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Affiliation(s)
- Roberta Cesa
- Department of Neuroscience, University of Turin, C.so Raffaello 30, 10125 Torino, Italy.
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49
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Kohda K, Kakegawa W, Matsuda S, Nakagami R, Kakiya N, Yuzaki M. The extreme C-terminus of GluRdelta2 is essential for induction of long-term depression in cerebellar slices. Eur J Neurosci 2007; 25:1357-62. [PMID: 17425562 DOI: 10.1111/j.1460-9568.2007.05412.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Long-term depression (LTD) of parallel fibre (PF)-Purkinje cell synapses in the cerebellum is recognized as a cellular substrate of motor learning. Although the delta2 glutamate receptor (GluRdelta2) has been shown to be crucial for LTD, the mechanisms by which GluRdelta2 functions remain elusive. In this study, we developed a virus vector-based gene transfer approach to rescue impaired LTD in GluRdelta2-null Purkinje cells in cerebellar slice preparations. We demonstrated that LTD was restored in GluRdelta2-null Purkinje cells transduced with wild-type but not with mutant GluRdelta2, which lacked the PDZ-ligand domain in the C-terminus. Immunohistochemical analysis revealed no difference in expression levels or spine localization patterns between virally introduced wild-type and mutant GluRdelta2 proteins. Similarly, LTD was abrogated in Purkinje cells that had been acutely perfused with peptides, hampering the interaction of GluRdelta2 with PDZ proteins such as PSD-93, PTPMEG and S-SCAM but not with delphilin. Together, these results indicate that PDZ proteins that bind to the C-terminus of GluRdelta2 are not essential for localizing GluRdelta2 at synapses but are crucial for conveying signals necessary for the induction of LTD.
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Affiliation(s)
- Kazuhisa Kohda
- Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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Gao J, Maison SF, Wu X, Hirose K, Jones SM, Bayazitov I, Tian Y, Mittleman G, Matthews DB, Zakharenko SS, Liberman MC, Zuo J. Orphan glutamate receptor delta1 subunit required for high-frequency hearing. Mol Cell Biol 2007; 27:4500-12. [PMID: 17438141 PMCID: PMC1900048 DOI: 10.1128/mcb.02051-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The function of the orphan glutamate receptor delta subunits (GluRdelta1 and GluRdelta2) remains unclear. GluRdelta2 is expressed exclusively in the Purkinje cells of the cerebellum, and GluRdelta1 is prominently expressed in inner ear hair cells and neurons of the hippocampus. We found that mice lacking the GluRdelta1 protein displayed significant cochlear threshold shifts for frequencies of >16 kHz. These deficits correlated with a substantial loss of type IV spiral ligament fibrocytes and a significant reduction of endolymphatic potential in high-frequency cochlear regions. Vulnerability to acoustic injury was significantly enhanced; however, the efferent innervation of hair cells and the classic efferent inhibition of outer hair cells were unaffected. Hippocampal and vestibular morphology and function were normal. Our findings show that the orphan GluRdelta1 plays an essential role in high-frequency hearing and ionic homeostasis in the basal cochlea, and the locus encoding GluRdelta1 represents a candidate gene for congenital or acquired high-frequency hearing loss in humans.
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Affiliation(s)
- Jiangang Gao
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
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