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Hizawa K, Sasaki T, Arimura N. A comparative overview of DSCAM and its multifunctional roles in Drosophila and vertebrates. Neurosci Res 2024; 202:1-7. [PMID: 38141781 DOI: 10.1016/j.neures.2023.12.005] [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: 10/19/2023] [Revised: 11/21/2023] [Accepted: 12/14/2023] [Indexed: 12/25/2023]
Abstract
DSCAM (Down syndrome cell adhesion molecule) is a unique neuronal adhesion protein with extensively documented multifaceted functionalities. DSCAM also has interesting properties in vertebrates and invertebrates, respectively. In Drosophila species, particularly, Dscam exhibits remarkable genetic diversity, with tens of thousands of splicing isoforms that modulate the specificity of neuronal wiring. Interestingly, this splice variant diversity of Dscam is absent in vertebrates. DSCAM plays a pivotal role in mitigating excessive adhesion between identical cell types, thereby maintaining the structural and functional coherence of neural networks. DSCAM contributes to the oversight of selective intercellular interactions such as synaptogenesis; however, the precise regulatory mechanisms underlying the promotion and inhibition of cell adhesion involved remain unclear. In this review, we aim to delineate the distinct molecules that interact with DSCAM and their specific roles within the biological landscapes of Drosophila and vertebrates. By integrating these comparative insights, we aim to elucidate the multifunctional nature of DSCAM, particularly its capacity to facilitate or deter intercellular adhesion.
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Affiliation(s)
- Kento Hizawa
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba Ward, Sendai, Miyagi 980-8578, Japan
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba Ward, Sendai, Miyagi 980-8578, Japan
| | - Nariko Arimura
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba Ward, Sendai, Miyagi 980-8578, Japan.
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2
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Nonaka H, Sakamoto S, Shiraiwa K, Ishikawa M, Tamura T, Okuno K, Kondo T, Kiyonaka S, Susaki EA, Shimizu C, Ueda HR, Kakegawa W, Arai I, Yuzaki M, Hamachi I. Bioorthogonal chemical labeling of endogenous neurotransmitter receptors in living mouse brains. Proc Natl Acad Sci U S A 2024; 121:e2313887121. [PMID: 38294939 PMCID: PMC10861872 DOI: 10.1073/pnas.2313887121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 12/16/2023] [Indexed: 02/02/2024] Open
Abstract
Neurotransmitter receptors are essential components of synapses for communication between neurons in the brain. Because the spatiotemporal expression profiles and dynamics of neurotransmitter receptors involved in many functions are delicately governed in the brain, in vivo research tools with high spatiotemporal resolution for receptors in intact brains are highly desirable. Covalent labeling by chemical reaction (chemical labeling) of proteins without genetic manipulation is now a powerful method for analyzing receptors in vitro. However, selective target receptor labeling in the brain has not yet been achieved. This study shows that ligand-directed alkoxyacylimidazole (LDAI) chemistry can be used to selectively tether synthetic probes to target endogenous receptors in living mouse brains. The reactive LDAI reagents with negative charges were found to diffuse well over the whole brain and could selectively label target endogenous receptors, including AMPAR, NMDAR, mGlu1, and GABAAR. This simple and robust labeling protocol was then used for various applications: three-dimensional spatial mapping of endogenous receptors in the brains of healthy and disease-model mice; multi-color receptor imaging; and pulse-chase analysis of the receptor dynamics in postnatal mouse brains. Here, results demonstrated that bioorthogonal receptor modification in living animal brains may provide innovative molecular tools that contribute to the in-depth understanding of complicated brain functions.
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Affiliation(s)
- Hiroshi Nonaka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto615-8510, Japan
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
| | - Seiji Sakamoto
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto615-8510, Japan
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
| | - Kazuki Shiraiwa
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto615-8510, Japan
| | - Mamoru Ishikawa
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
| | - Tomonori Tamura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto615-8510, Japan
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
| | - Kyohei Okuno
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto615-8510, Japan
| | - Takumi Kondo
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya464-8603, Japan
| | - Shigeki Kiyonaka
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya464-8603, Japan
| | - Etsuo A. Susaki
- Department of Biochemistry and Systems Biomedicine, Juntendo University Graduate School of Medicine, Tokyo113-8421, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka 565-5241, Japan
| | - Chika Shimizu
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka 565-5241, Japan
| | - Hiroki R. Ueda
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka 565-5241, Japan
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo113-0033, Japan
| | - Wataru Kakegawa
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
- Department of Neurophysiology, Keio University School of Medicine, Tokyo160-8582, Japan
| | - Itaru Arai
- Department of Neurophysiology, Keio University School of Medicine, Tokyo160-8582, Japan
| | - Michisuke Yuzaki
- Department of Neurophysiology, Keio University School of Medicine, Tokyo160-8582, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto615-8510, Japan
- Hamachi Innovative Molecular Technology for Neuroscience, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Kyoto615-8530, Japan
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3
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Dewa KI, Arimura N, Kakegawa W, Itoh M, Adachi T, Miyashita S, Inoue YU, Hizawa K, Hori K, Honjoya N, Yagishita H, Taya S, Miyazaki T, Usui C, Tatsumoto S, Tsuzuki A, Uetake H, Sakai K, Yamakawa K, Sasaki T, Nagai J, Kawaguchi Y, Sone M, Inoue T, Go Y, Ichinohe N, Kaibuchi K, Watanabe M, Koizumi S, Yuzaki M, Hoshino M. Neuronal DSCAM regulates the peri-synaptic localization of GLAST in Bergmann glia for functional synapse formation. Nat Commun 2024; 15:458. [PMID: 38302444 PMCID: PMC10834496 DOI: 10.1038/s41467-023-44579-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 12/19/2023] [Indexed: 02/03/2024] Open
Abstract
In the central nervous system, astrocytes enable appropriate synapse function through glutamate clearance from the synaptic cleft; however, it remains unclear how astrocytic glutamate transporters function at peri-synaptic contact. Here, we report that Down syndrome cell adhesion molecule (DSCAM) in Purkinje cells controls synapse formation and function in the developing cerebellum. Dscam-mutant mice show defects in CF synapse translocation as is observed in loss of function mutations in the astrocytic glutamate transporter GLAST expressed in Bergmann glia. These mice show impaired glutamate clearance and the delocalization of GLAST away from the cleft of parallel fibre (PF) synapse. GLAST complexes with the extracellular domain of DSCAM. Riluzole, as an activator of GLAST-mediated uptake, rescues the proximal impairment in CF synapse formation in Purkinje cell-selective Dscam-deficient mice. DSCAM is required for motor learning, but not gross motor coordination. In conclusion, the intercellular association of synaptic and astrocyte proteins is important for synapse formation and function in neural transmission.
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Affiliation(s)
- Ken-Ichi Dewa
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Nariko Arimura
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan.
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan.
| | - Wataru Kakegawa
- Department of Physiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Masayuki Itoh
- Department of Physiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Toma Adachi
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Satoshi Miyashita
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Department of System Pathology for Neurological Disorders, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Yukiko U Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Kento Hizawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Kei Hori
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Natsumi Honjoya
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Haruya Yagishita
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Shinichiro Taya
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Division of Behavioural Neuropharmacology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Taisuke Miyazaki
- Department of Health Sciences, School of Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0812, Japan
| | - Chika Usui
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
| | - Shoji Tatsumoto
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
| | - Akiko Tsuzuki
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Hirotomo Uetake
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Saitama, 274-8510, Japan
| | - Kazuhisa Sakai
- Department of Ultrastructural Research, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Kazuhiro Yamakawa
- Department of Neurodevelopmental Disorder Genetics, Nagoya City University Graduate School of Medicine, Nagoya, Aichi, 467-8601, Japan
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Jun Nagai
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Yoshiya Kawaguchi
- Department of Life Science Frontiers, Center for iPS cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Masaki Sone
- Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Saitama, 274-8510, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Yasuhiro Go
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
- Department of System Neuroscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
- Graduate School of Information Science, University of Hyogo, Kobe, Hyogo, 650-0047, Japan
| | - Noritaka Ichinohe
- Department of Ultrastructural Research, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Kozo Kaibuchi
- Division of Cell Biology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Hokkaido, 060-8638, Japan
- The University of Texas at Austin, Austin, Texas, 78712-0805, USA
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan.
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Kim M, Jun S, Park H, Tanaka-Yamamoto K, Yamamoto Y. Regulation of cerebellar network development by granule cells and their molecules. Front Mol Neurosci 2023; 16:1236015. [PMID: 37520428 PMCID: PMC10375027 DOI: 10.3389/fnmol.2023.1236015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 06/27/2023] [Indexed: 08/01/2023] Open
Abstract
The well-organized cerebellar structures and neuronal networks are likely crucial for their functions in motor coordination, motor learning, cognition, and emotion. Such cerebellar structures and neuronal networks are formed during developmental periods through orchestrated mechanisms, which include not only cell-autonomous programs but also interactions between the same or different types of neurons. Cerebellar granule cells (GCs) are the most numerous neurons in the brain and are generated through intensive cell division of GC precursors (GCPs) during postnatal developmental periods. While GCs go through their own developmental processes of proliferation, differentiation, migration, and maturation, they also play a crucial role in cerebellar development. One of the best-characterized contributions is the enlargement and foliation of the cerebellum through massive proliferation of GCPs. In addition to this contribution, studies have shown that immature GCs and GCPs regulate multiple factors in the developing cerebellum, such as the development of other types of cerebellar neurons or the establishment of afferent innervations. These studies have often found impairments of cerebellar development in animals lacking expression of certain molecules in GCs, suggesting that the regulations are mediated by molecules that are secreted from or present in GCs. Given the growing recognition of GCs as regulators of cerebellar development, this review will summarize our current understanding of cerebellar development regulated by GCs and molecules in GCs, based on accumulated studies and recent findings, and will discuss their potential further contributions.
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Affiliation(s)
- Muwoong Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology (UST), Seoul, Republic of Korea
| | - Soyoung Jun
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology (UST), Seoul, Republic of Korea
| | - Heeyoun Park
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Keiko Tanaka-Yamamoto
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology (UST), Seoul, Republic of Korea
| | - Yukio Yamamoto
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
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5
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Zhang J, Wei K, Qu W, Wang M, Zhu Q, Dong X, Huang X, Yi W, Xu S, Li X. Ogt Deficiency Induces Abnormal Cerebellar Function and Behavioral Deficits of Adult Mice through Modulating RhoA/ROCK Signaling. J Neurosci 2023; 43:4559-4579. [PMID: 37225434 PMCID: PMC10286951 DOI: 10.1523/jneurosci.1962-22.2023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 04/10/2023] [Accepted: 04/13/2023] [Indexed: 05/26/2023] Open
Abstract
Previous studies have shown the essential roles of O-GlcNAc transferase (Ogt) and O-GlcNAcylation in neuronal development, function and neurologic diseases. However, the function of Ogt and O-GlcNAcylation in the adult cerebellum has not been well elucidated. Here, we have found that cerebellum has the highest level of O-GlcNAcylation relative to cortex and hippocampus of adult male mice. Specific deletion of Ogt in granule neuron precursors (GNPs) induces abnormal morphology and decreased size of the cerebellum in adult male Ogt deficient [conditional knock-out (cKO)] mice. Adult male cKO mice show the reduced density and aberrant distribution of cerebellar granule cells (CGCs), the disrupted arrangement of Bergman glia (BG) and Purkinje cells. In addition, adult male cKO mice exhibit aberrant synaptic connection, impaired motor coordination, and learning and memory abilities. Mechanistically, we have identified G-protein subunit α12 (Gα12) is modified by Ogt-mediated O-GlcNAcylation. O-GlcNAcylation of Gα12 facilitates its binding to Rho guanine nucleotide exchange factor 12 (Arhgef12) and consequently activates RhoA/ROCK signaling. RhoA/ROCK pathway activator LPA can rescue the developmental deficits of Ogt deficient CGCs. Therefore, our study has revealed the critical function and related mechanisms of Ogt and O-GlcNAcylation in the cerebellum of adult male mice.SIGNIFICANCE STATEMENT Cerebellar function are regulated by diverse mechanisms. To unveil novel mechanisms is critical for understanding the cerebellar function and the clinical therapy of cerebellum-related diseases. In the present study, we have shown that O-GlcNAc transferase gene (Ogt) deletion induces abnormal cerebellar morphology, synaptic connection, and behavioral deficits of adult male mice. Mechanistically, Ogt catalyzes O-GlcNAcylation of Gα12, which promotes the binding to Arhgef12, and regulates RhoA/ROCK signaling pathway. Our study has uncovered the important roles of Ogt and O-GlcNAcylation in regulating cerebellar function and cerebellum-related behavior. Our results suggest that Ogt and O-GlcNAcylation could be potential targets for some cerebellum-related diseases.
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Affiliation(s)
- Jinyu Zhang
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Kaiyan Wei
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
| | - Wenzheng Qu
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
| | - Mengxuan Wang
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Qiang Zhu
- MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou 310058
- The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310002, China
| | - Xiaoxue Dong
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Xiaoli Huang
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
| | - Wen Yi
- MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou 310058
- The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310002, China
| | - Shunliang Xu
- Department of Neurology, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250033, China
| | - Xuekun Li
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Diagnosis and Treatment of Neonatal Diseases of Zhejiang Province, Hangzhou 310052, China
- Binjiang Institute of Zhejiang University, Hangzhou 310053, China
- Zhejiang University Cancer Center, Zhejiang University, Hangzhou 310029, China
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6
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Osório C, White JJ, Lu H, Beekhof GC, Fiocchi FR, Andriessen CA, Dijkhuizen S, Post L, Schonewille M. Pre-ataxic loss of intrinsic plasticity and motor learning in a mouse model of SCA1. Brain 2023; 146:2332-2345. [PMID: 36352508 PMCID: PMC10232256 DOI: 10.1093/brain/awac422] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 10/04/2022] [Accepted: 10/24/2022] [Indexed: 12/29/2023] Open
Abstract
Spinocerebellar ataxias are neurodegenerative diseases, the hallmark symptom of which is the development of ataxia due to cerebellar dysfunction. Purkinje cells, the principal neurons of the cerebellar cortex, are the main cells affected in these disorders, but the sequence of pathological events leading to their dysfunction is poorly understood. Understanding the origins of Purkinje cells dysfunction before it manifests is imperative to interpret the functional and behavioural consequences of cerebellar-related disorders, providing an optimal timeline for therapeutic interventions. Here, we report the cascade of events leading to Purkinje cells dysfunction before the onset of ataxia in a mouse model of spinocerebellar ataxia 1 (SCA1). Spatiotemporal characterization of the ATXN1[82Q] SCA1 mouse model revealed high levels of the mutant ATXN1[82Q] weeks before the onset of ataxia. The expression of the toxic protein first caused a reduction of Purkinje cells intrinsic excitability, which was followed by atrophy of Purkinje cells dendrite arborization and aberrant glutamatergic signalling, finally leading to disruption of Purkinje cells innervation of climbing fibres and loss of intrinsic plasticity of Purkinje cells. Functionally, we found that deficits in eyeblink conditioning, a form of cerebellum-dependent motor learning, precede the onset of ataxia, matching the timeline of climbing fibre degeneration and reduced intrinsic plasticity. Together, our results suggest that abnormal synaptic signalling and intrinsic plasticity during the pre-ataxia stage of spinocerebellar ataxias underlie an aberrant cerebellar circuitry that anticipates the full extent of the disease severity. Furthermore, our work indicates the potential for eyeblink conditioning to be used as a sensitive tool to detect early cerebellar dysfunction as a sign of future disease.
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Affiliation(s)
- Catarina Osório
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
| | - Joshua J White
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
| | - Heiling Lu
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
| | - Gerrit C Beekhof
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
| | | | | | - Stephanie Dijkhuizen
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
| | - Laura Post
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
| | - Martijn Schonewille
- Department of Neuroscience, Erasmus Medical Center, Rotterdam 3015CN, The Netherlands
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7
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Nicoletti F, Di Menna L, Iacovelli L, Orlando R, Zuena AR, Conn PJ, Dogra S, Joffe ME. GPCR interactions involving metabotropic glutamate receptors and their relevance to the pathophysiology and treatment of CNS disorders. Neuropharmacology 2023; 235:109569. [PMID: 37142158 DOI: 10.1016/j.neuropharm.2023.109569] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/18/2023] [Accepted: 05/02/2023] [Indexed: 05/06/2023]
Abstract
Cellular responses to metabotropic glutamate (mGlu) receptor activation are shaped by mechanisms of receptor-receptor interaction. mGlu receptor subtypes form homodimers, intra- or inter-group heterodimers, and heteromeric complexes with other G protein-coupled receptors (GPCRs). In addition, mGlu receptors may functionally interact with other receptors through the βγ subunits released from G proteins in response to receptor activation or other mechanisms. Here, we discuss the interactions between (i) mGlu1 and GABAB receptors in cerebellar Purkinje cells; (ii) mGlu2 and 5-HT2Aserotonergic receptors in the prefrontal cortex; (iii) mGlu5 and A2A receptors or mGlu5 and D1 dopamine receptors in medium spiny projection neurons of the indirect and direct pathways of the basal ganglia motor circuit; (iv) mGlu5 and A2A receptors in relation to the pathophysiology of Alzheimer's disease; and (v) mGlu7 and A1 adenosine or α- or β1 adrenergic receptors. In addition, we describe in detail a novel form of non-heterodimeric interaction between mGlu3 and mGlu5 receptors, which appears to be critically involved in mechanisms of activity-dependent synaptic plasticity in the prefrontal cortex and hippocampus. Finally, we highlight the potential implication of these interactions in the pathophysiology and treatment of cerebellar disorders, schizophrenia, Alzheimer's disease, Parkinson's disease, l-DOPA-induced dyskinesias, stress-related disorders, and cognitive dysfunctions.
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Affiliation(s)
- Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli, Italy.
| | | | - Luisa Iacovelli
- Department of Physiology and Pharmacology, Sapienza University of Rome, Italy
| | - Rosamaria Orlando
- Department of Physiology and Pharmacology, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Anna Rita Zuena
- Department of Physiology and Pharmacology, Sapienza University of Rome, Italy
| | - P Jeffrey Conn
- Department of Pharmacology, Italy; Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
| | - Shalini Dogra
- Department of Pharmacology, Italy; Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
| | - Max E Joffe
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
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8
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Wang XT, Zhou L, Dong BB, Xu FX, Wang DJ, Shen EW, Cai XY, Wang Y, Wang N, Ji SJ, Chen W, Schonewille M, Zhu JJ, De Zeeuw CI, Shen Y. cAMP-EPAC-PKCε-RIM1α signaling regulates presynaptic long-term potentiation and motor learning. eLife 2023; 12:e80875. [PMID: 37159499 PMCID: PMC10171863 DOI: 10.7554/elife.80875] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 04/25/2023] [Indexed: 05/11/2023] Open
Abstract
The cerebellum is involved in learning of fine motor skills, yet whether presynaptic plasticity contributes to such learning remains elusive. Here, we report that the EPAC-PKCε module has a critical role in a presynaptic form of long-term potentiation in the cerebellum and motor behavior in mice. Presynaptic cAMP-EPAC-PKCε signaling cascade induces a previously unidentified threonine phosphorylation of RIM1α, and thereby initiates the assembly of the Rab3A-RIM1α-Munc13-1 tripartite complex that facilitates docking and release of synaptic vesicles. Granule cell-specific blocking of EPAC-PKCε signaling abolishes presynaptic long-term potentiation at the parallel fiber to Purkinje cell synapses and impairs basic performance and learning of cerebellar motor behavior. These results unveil a functional relevance of presynaptic plasticity that is regulated through a novel signaling cascade, thereby enriching the spectrum of cerebellar learning mechanisms.
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Affiliation(s)
- Xin-Tai Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
- Institute of Life Sciences, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
| | - Lin Zhou
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Bin-Bin Dong
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Fang-Xiao Xu
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - De-Juan Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - En-Wei Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Xin-Yu Cai
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Yin Wang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical UniversityYinchuanChina
| | - Na Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Sheng-Jian Ji
- Department of Biology, Southern University of Science and TechnologyShenzhenChina
| | - Wei Chen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | | | - J Julius Zhu
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MCRotterdamNetherlands
- Netherlands Institute for Neuroscience, Royal Academy of SciencesAmsterdamNetherlands
| | - Ying Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
- International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of MedicineYiwuChina
- Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of MedicineHangzhouChina
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9
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Kim S, Ochoa K, Melli SE, Yousufzai FAK, Barrera ZD, Williams AA, McIntyre G, Delgado E, Bolish JN, Macleod CM, Boghos M, Lens HP, Ramos AG, Wilson VB, Maloney K, Padron ZM, Khan AH, Blanco RE, Soto I. Disruptive lysosomal-metabolic signaling and neurodevelopmental deficits that precede Purkinje cell loss in a mouse model of Niemann-Pick Type-C disease. Sci Rep 2023; 13:5665. [PMID: 37024714 PMCID: PMC10079843 DOI: 10.1038/s41598-023-32971-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 04/05/2023] [Indexed: 04/08/2023] Open
Abstract
Purkinje cell (PC) loss occurs at an early age in patients and animal models of Niemann-Pick Type C (NPC), a lysosomal storage disease caused by mutations in the Npc1 or Npc2 genes. Although degeneration of PCs occurs early in NPC, little is known about how NPC1 deficiency affects the postnatal development of PCs. Using the Npc1nmf164 mouse model, we found that NPC1 deficiency significantly affected the postnatal development of PC dendrites and synapses. The developing dendrites of Npc1nmf164 PCs were significantly deficient in mitochondria and lysosomes. Furthermore, anabolic (mTORC1) and catabolic (TFEB) signaling pathways were not only perturbed but simultaneously activated in NPC1-deficient PCs, suggesting a loss of metabolic balance. We also found that mice with conditional heterozygous deletion of the Phosphatase and Tensin Homolog Deleted on Chromosome 10 gene (Pten-cHet), an inhibitor of mTORC1, showed similar early dendritic alterations in PCs to those found in Npc1-deficient mice. However, in contrast to Npc1nmf164 mice, Pten-cHet mice exhibited the overactivation of the mTORC1 pathway but with a strong inhibition of TFEB signaling, along with no dendritic mitochondrial reductions by the end of their postnatal development. Our data suggest that disruption of the lysosomal-metabolic signaling in PCs causes dendritic and synaptic developmental deficits that precede and promote their early degeneration in NPC.
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Affiliation(s)
- Sarah Kim
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Kathleen Ochoa
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Sierra E Melli
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Fawad A K Yousufzai
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Zerian D Barrera
- Department of Biological Science, Rowan University, Glassboro, NJ, USA
| | - Aela A Williams
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ, USA
| | - Gianna McIntyre
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Esteban Delgado
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - James N Bolish
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ, USA
| | | | - Mary Boghos
- Department of Biology, Providence College, Providence, RI, USA
| | - Hayden P Lens
- Department of Biology, Providence College, Providence, RI, USA
| | - Alex G Ramos
- Department of Biology, Providence College, Providence, RI, USA
| | - Vincent B Wilson
- Department of Biological Science, Rowan University, Glassboro, NJ, USA
| | - Kelly Maloney
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Zachary M Padron
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Amaal H Khan
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ, USA
| | - Rosa E Blanco
- The Institute of Neurobiology, University of Puerto Rico, San Juan, PR, USA
| | - Ileana Soto
- Department of Biology, Providence College, Providence, RI, USA.
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10
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Targeting mGlu1 Receptors in the Treatment of Motor and Cognitive Dysfunctions in Mice Modeling Type 1 Spinocerebellar Ataxia. Cells 2022; 11:cells11233916. [PMID: 36497172 PMCID: PMC9738505 DOI: 10.3390/cells11233916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/09/2022] Open
Abstract
Type 1 spinocerebellar ataxia (SCA1) is a progressive neurodegenerative disorder with no effective treatment to date. Using mice modeling SCA1, it has been demonstrated that a drug that amplifies mGlu1 receptor activation (mGlu1 receptor PAM, Ro0711401) improves motor coordination without the development of tolerance when cerebellar dysfunction manifests (i.e., in 30-week-old heterozygous ataxin-1 [154Q/2Q] transgenic mice). SCA1 is also associated with cognitive dysfunction, which may precede cerebellar motor signs. Here, we report that otherwise healthy, 8-week-old SCA1 mice showed a defect in spatial learning and memory associated with reduced protein levels of mGlu1α receptors, the GluN2B subunit of NMDA receptors, and cannabinoid CB1 receptors in the hippocampus. Systemic treatment with Ro0711401 (10 mg/kg, s.c.) partially corrected the learning deficit in the Morris water maze and restored memory retention in the SCA1 mice model. This treatment also enhanced hippocampal levels of the endocannabinoid, anandamide, without changing the levels of 2-arachidonylglycerol. These findings suggest that mGlu1 receptor PAMs may be beneficial in the treatment of motor and nonmotor signs associated with SCA1 and encourage further studies in animal models of SCA1 and other types of SCAs.
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11
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Simmons DH, Busch SE, Titley HK, Grasselli G, Shih J, Du X, Wei C, Gomez CM, Piochon C, Hansel C. Sensory Over-responsivity and Aberrant Plasticity in Cerebellar Cortex in a Mouse Model of Syndromic Autism. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2022; 2:450-459. [PMID: 36324646 PMCID: PMC9616247 DOI: 10.1016/j.bpsgos.2021.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/15/2021] [Accepted: 09/17/2021] [Indexed: 11/28/2022] Open
Abstract
Background Patients with autism spectrum disorder often show altered responses to sensory stimuli as well as motor deficits, including an impairment of delay eyeblink conditioning, which involves integration of sensory signals in the cerebellum. Here, we identify abnormalities in parallel fiber (PF) and climbing fiber (CF) signaling in the mouse cerebellar cortex that may contribute to these pathologies. Methods We used a mouse model for the human 15q11-13 duplication (patDp/+) and studied responses to sensory stimuli in Purkinje cells from awake mice using two-photon imaging of GCaMP6f signals. Moreover, we examined synaptic transmission and plasticity using in vitro electrophysiological, immunohistochemical, and confocal microscopic techniques. Results We found that spontaneous and sensory-evoked CF-calcium transients are enhanced in patDp/+ Purkinje cells, and aversive movements are more severe across sensory modalities. We observed increased expression of the synaptic organizer NRXN1 at CF synapses and ectopic spread of these synapses to fine dendrites. CF-excitatory postsynaptic currents recorded from Purkinje cells are enlarged in patDp/+ mice, while responses to PF stimulation are reduced. Confocal measurements show reduced PF+CF-evoked spine calcium transients, a key trigger for PF long-term depression, one of several plasticity types required for eyeblink conditioning learning. Long-term depression is impaired in patDp/+ mice but is rescued on pharmacological enhancement of calcium signaling. Conclusions Our findings suggest that this genetic abnormality causes a pathological inflation of CF signaling, possibly resulting from enhanced NRXN1 expression, with consequences for the representation of sensory stimuli by the CF input and for PF synaptic organization and plasticity.
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Affiliation(s)
- Dana H Simmons
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Silas E Busch
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Heather K Titley
- Department of Neurobiology, University of Chicago, Chicago, Illinois.,Department of Nursing, University of Alberta, Edmonton, Alberta, Canada
| | - Giorgio Grasselli
- Department of Neurobiology, University of Chicago, Chicago, Illinois.,Istituto Italiano di Tecnologia, Center for Synaptic Neuroscience and Technology, Genoa, Italy.,IRCC Ospedale Policlinico San Martino, Genoa, Italy
| | - Justine Shih
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Xiaofei Du
- Department of Neurology, University of Chicago, Chicago, Illinois
| | - Cenfu Wei
- Department of Neurology, University of Chicago, Chicago, Illinois
| | | | - Claire Piochon
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Christian Hansel
- Department of Neurobiology, University of Chicago, Chicago, Illinois
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12
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Modified climbing fiber/Purkinje cell synaptic connectivity in the cerebellum of the neonatal phencyclidine model of schizophrenia. Proc Natl Acad Sci U S A 2022; 119:e2122544119. [PMID: 35588456 PMCID: PMC9173783 DOI: 10.1073/pnas.2122544119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Synaptogenesis and neural network remodeling are at their maximum during the perinatal period of human brain development. Perturbations of this highly sensitive stage might underlie the etiology of neurodevelopmental disorders. Subchronic neonatal administration of phencyclidine, a drug of abuse, has been used to model schizophrenia in rodents. In this model, we found specific long-term synaptic changes in Purkinje cells and transient gene expression changes in the cerebellum. While transient increased neuronal activity in the cerebellum, induced using chemogenetics, reproduces some phencyclidine-induced molecular changes, it is insufficient to reproduce the long-term synaptic effects. Our results show the complex mechanism of action of phencyclidine on the development of neuronal connectivity and further highlight the potential contribution of cerebellar defects in psychiatric diseases. Environmental perturbations during the first years of life are a major factor in psychiatric diseases. Phencyclidine (PCP), a drug of abuse, has psychomimetic effects, and neonatal subchronic administration of PCP in rodents leads to long-term behavioral changes relevant for schizophrenia. The cerebellum is increasingly recognized for its role in diverse cognitive functions. However, little is known about potential cerebellar changes in models of schizophrenia. Here, we analyzed the characteristics of the cerebellum in the neonatal subchronic PCP model. We found that, while the global cerebellar cytoarchitecture and Purkinje cell spontaneous spiking properties are unchanged, climbing fiber/Purkinje cell synaptic connectivity is increased in juvenile mice. Neonatal subchronic administration of PCP is accompanied by increased cFos expression, a marker of neuronal activity, and transient modification of the neuronal surfaceome in the cerebellum. The largest change observed is the overexpression of Ctgf, a gene previously suggested as a biomarker for schizophrenia. This neonatal increase in Ctgf can be reproduced by increasing neuronal activity in the cerebellum during the second postnatal week using chemogenetics. However, it does not lead to increased climbing fiber/Purkinje cell connectivity in juvenile mice, showing the complexity of PCP action. Overall, our study shows that administration of the drug of abuse PCP during the developmental period of intense cerebellar synaptogenesis and circuit remodeling has long-term and specific effects on Purkinje cell connectivity and warrants the search for this type of synaptic changes in psychiatric diseases.
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13
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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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14
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Nicoletti F. Along the path paved by Watkins and Evans: metabotropic glutamate receptors, from the discovery to clinical applications. Neuropharmacology 2022; 208:108949. [PMID: 35033533 DOI: 10.1016/j.neuropharm.2022.108949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ferdinando Nicoletti
- Department of Physiology Ad Pharmacology, University Sapienza of Rome, IRCCS Euromed, Pozzilli, Italy.
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15
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Loschky SS, Spano GM, Marshall W, Schroeder A, Nemec KM, Schiereck SS, de Vivo L, Bellesi M, Banningh SW, Tononi G, Cirelli C. Ultrastructural effects of sleep and wake on the parallel fiber synapses of the cerebellum. eLife 2022; 11:84199. [PMID: 36576248 PMCID: PMC9797193 DOI: 10.7554/elife.84199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/18/2022] [Indexed: 12/29/2022] Open
Abstract
Multiple evidence in rodents shows that the strength of excitatory synapses in the cerebral cortex and hippocampus is greater after wake than after sleep. The widespread synaptic weakening afforded by sleep is believed to keep the cost of synaptic activity under control, promote memory consolidation, and prevent synaptic saturation, thus preserving the brain's ability to learn day after day. The cerebellum is highly plastic and the Purkinje cells, the sole output neurons of the cerebellar cortex, are endowed with a staggering number of excitatory parallel fiber synapses. However, whether these synapses are affected by sleep and wake is unknown. Here, we used serial block face scanning electron microscopy to obtain the full 3D reconstruction of more than 7000 spines and their parallel fiber synapses in the mouse posterior vermis. This analysis was done in mice whose cortical and hippocampal synapses were previously measured, revealing that average synaptic size was lower after sleep compared to wake with no major changes in synapse number. Here, instead, we find that while the average size of parallel fiber synapses does not change, the number of branched synapses is reduced in half after sleep compared to after wake, corresponding to ~16% of all spines after wake and ~8% after sleep. Branched synapses are harbored by two or more spines sharing the same neck and, as also shown here, are almost always contacted by different parallel fibers. These findings suggest that during wake, coincidences of firing over parallel fibers may translate into the formation of synapses converging on the same branched spine, which may be especially effective in driving Purkinje cells to fire. By contrast, sleep may promote the off-line pruning of branched synapses that were formed due to spurious coincidences.
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Affiliation(s)
- Sophia S Loschky
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
| | | | - William Marshall
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States,Department of Mathematics and Statistics, Brock UniversitySt. CatharinesCanada
| | - Andrea Schroeder
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
| | - Kelsey Marie Nemec
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
| | | | - Luisa de Vivo
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
| | - Michele Bellesi
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
| | | | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-MadisonMadisonUnited States
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16
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Dhanya SK, Hasan G. Deficits Associated With Loss of STIM1 in Purkinje Neurons Including Motor Coordination Can Be Rescued by Loss of Septin 7. Front Cell Dev Biol 2021; 9:794807. [PMID: 34993201 PMCID: PMC8724567 DOI: 10.3389/fcell.2021.794807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/15/2021] [Indexed: 12/26/2022] Open
Abstract
Septins are cytoskeletal proteins that can assemble to form heteromeric filamentous complexes and regulate a range of membrane-associated cellular functions. SEPT7, a member of the septin family, functions as a negative regulator of the plasma membrane–localized store-operated Ca2+ entry (SOCE) channel, Orai in Drosophila neurons, and in human neural progenitor cells. Knockdown of STIM, a Ca2+ sensor in the endoplasmic reticulum (ER) and an integral component of SOCE, leads to flight deficits in Drosophila that can be rescued by partial loss of SEPT7 in neurons. Here, we tested the effect of reducing and removing SEPT7 in mouse Purkinje neurons (PNs) with the loss of STIM1. Mice with the complete knockout of STIM1 in PNs exhibit several age-dependent changes. These include altered gene expression in PNs, which correlates with increased synapses between climbing fiber (CF) axons and Purkinje neuron (PN) dendrites and a reduced ability to learn a motor coordination task. Removal of either one or two copies of the SEPT7 gene in STIM1KO PNs restored the expression of a subset of genes, including several in the category of neuron projection development. Importantly, the rescue of gene expression in these animals is accompanied by normal CF-PN innervation and an improved ability to learn a motor coordination task in aging mice. Thus, the loss of SEPT7 in PNs further modulates cerebellar circuit function in STIM1KO animals. Our findings are relevant in the context of identifying SEPT7 as a putative therapeutic target for various neurodegenerative diseases caused by reduced intracellular Ca2+ signaling.
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Affiliation(s)
- Sreeja Kumari Dhanya
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- SASTRA University, Thanjavur, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- *Correspondence: Gaiti Hasan,
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17
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Faust TE, Gunner G, Schafer DP. Mechanisms governing activity-dependent synaptic pruning in the developing mammalian CNS. Nat Rev Neurosci 2021; 22:657-673. [PMID: 34545240 PMCID: PMC8541743 DOI: 10.1038/s41583-021-00507-y] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2021] [Indexed: 02/08/2023]
Abstract
Almost 60 years have passed since the initial discovery by Hubel and Wiesel that changes in neuronal activity can elicit developmental rewiring of the central nervous system (CNS). Over this period, we have gained a more comprehensive picture of how both spontaneous neural activity and sensory experience-induced changes in neuronal activity guide CNS circuit development. Here we review activity-dependent synaptic pruning in the mammalian CNS, which we define as the removal of a subset of synapses, while others are maintained, in response to changes in neural activity in the developing nervous system. We discuss the mounting evidence that immune and cell-death molecules are important mechanistic links by which changes in neural activity guide the pruning of specific synapses, emphasizing the role of glial cells in this process. Finally, we discuss how these developmental pruning programmes may go awry in neurodevelopmental disorders of the human CNS, focusing on autism spectrum disorder and schizophrenia. Together, our aim is to give an overview of how the field of activity-dependent pruning research has evolved, led to exciting new questions and guided the identification of new, therapeutically relevant mechanisms that result in aberrant circuit development in neurodevelopmental disorders.
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Affiliation(s)
- Travis E Faust
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Georgia Gunner
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Dorothy P Schafer
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA.
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18
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Parajuli LK, Koike M. Three-Dimensional Structure of Dendritic Spines Revealed by Volume Electron Microscopy Techniques. Front Neuroanat 2021; 15:627368. [PMID: 34135737 PMCID: PMC8200415 DOI: 10.3389/fnana.2021.627368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 05/03/2021] [Indexed: 11/13/2022] Open
Abstract
Electron microscopy (EM)-based synaptology is a fundamental discipline for achieving a complex wiring diagram of the brain. A quantitative understanding of synaptic ultrastructure also serves as a basis to estimate the relative magnitude of synaptic transmission across individual circuits in the brain. Although conventional light microscopic techniques have substantially contributed to our ever-increasing understanding of the morphological characteristics of the putative synaptic junctions, EM is the gold standard for systematic visualization of the synaptic morphology. Furthermore, a complete three-dimensional reconstruction of an individual synaptic profile is required for the precise quantitation of different parameters that shape synaptic transmission. While volumetric imaging of synapses can be routinely obtained from the transmission EM (TEM) imaging of ultrathin sections, it requires an unimaginable amount of effort and time to reconstruct very long segments of dendrites and their spines from the serial section TEM images. The challenges of low throughput EM imaging have been addressed to an appreciable degree by the development of automated EM imaging tools that allow imaging and reconstruction of dendritic segments in a realistic time frame. Here, we review studies that have been instrumental in determining the three-dimensional ultrastructure of synapses. With a particular focus on dendritic spine synapses in the rodent brain, we discuss various key studies that have highlighted the structural diversity of spines, the principles of their organization in the dendrites, their presynaptic wiring patterns, and their activity-dependent structural remodeling.
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Affiliation(s)
- Laxmi Kumar Parajuli
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masato Koike
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Advanced Research Institute for Health Science, Juntendo University, Tokyo, Japan
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19
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Purkinje Neurons with Loss of STIM1 Exhibit Age-Dependent Changes in Gene Expression and Synaptic Components. J Neurosci 2021; 41:3777-3798. [PMID: 33737457 DOI: 10.1523/jneurosci.2401-20.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/13/2022] Open
Abstract
The stromal interaction molecule 1 (STIM1) is an ER-Ca2+ sensor and an essential component of ER-Ca2+ store operated Ca2+ entry. Loss of STIM1 affects metabotropic glutamate receptor 1 (mGluR1)-mediated synaptic transmission, neuronal Ca2+ homeostasis, and intrinsic plasticity in Purkinje neurons (PNs). Long-term changes of intracellular Ca2+ signaling in PNs led to neurodegenerative conditions, as evident in individuals with mutations of the ER-Ca2+ channel, the inositol 1,4,5-triphosphate receptor. Here, we asked whether changes in such intrinsic neuronal properties, because of loss of STIM1, have an age-dependent impact on PNs. Consequently, we analyzed mRNA expression profiles and cerebellar morphology in PN-specific STIM1 KO mice (STIM1PKO ) of both sexes across ages. Our study identified a requirement for STIM1-mediated Ca2+ signaling in maintaining the expression of genes belonging to key biological networks of synaptic function and neurite development among others. Gene expression changes correlated with altered patterns of dendritic morphology and greater innervation of PN dendrites by climbing fibers, in aging STIM1PKO mice. Together, our data identify STIM1 as an important regulator of Ca2+ homeostasis and neuronal excitability in turn required for maintaining the optimal transcriptional profile of PNs with age. Our findings are significant in the context of understanding how dysregulated calcium signals impact cellular mechanisms in multiple neurodegenerative disorders.SIGNIFICANCE STATEMENT In Purkinje neurons (PNs), the stromal interaction molecule 1 (STIM1) is required for mGluR1-dependent synaptic transmission, refilling of ER Ca2+ stores, regulation of spike frequency, and cerebellar memory consolidation. Here, we provide evidence for a novel role of STIM1 in maintaining the gene expression profile and optimal synaptic connectivity of PNs. Expression of genes related to neurite development and synaptic organization networks is altered in PNs with persistent loss of STIM1. In agreement with these findings the dendritic morphology of PNs and climbing fiber innervations on PNs also undergo significant changes with age. These findings identify a new role for dysregulated intracellular calcium signaling in neurodegenerative disorders and provide novel therapeutic insights.
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20
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Wang XT, Zhou L, Cai XY, Xu FX, Xu ZH, Li XY, Shen Y. Deletion of Mea6 in Cerebellar Granule Cells Impairs Synaptic Development and Motor Performance. Front Cell Dev Biol 2021; 8:627146. [PMID: 33718348 PMCID: PMC7946997 DOI: 10.3389/fcell.2020.627146] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 12/21/2020] [Indexed: 01/04/2023] Open
Abstract
The cerebellum is conceptualized as a processor of complex movements. Many diseases with gene-targeted mutations, including Fahr’s disease associated with the loss-of-function mutation of meningioma expressed antigen 6 (Mea6), exhibit cerebellar malformations, and abnormal motor behaviors. We previously reported that the defects in cerebellar development and motor performance of Nestin-Cre;Mea6F/F mice are severer than those of Purkinje cell-targeted pCP2-Cre;Mea6F/F mice, suggesting that Mea6 acts on other types of cerebellar cells. Hence, we investigated the function of Mea6 in cerebellar granule cells. We found that mutant mice with the specific deletion of Mea6 in granule cells displayed abnormal posture, balance, and motor learning, as indicated in footprint, head inclination, balanced beam, and rotarod tests. We further showed that Math1-Cre;Mea6F/F mice exhibited disrupted migration of granule cell progenitors and damaged parallel fiber-Purkinje cell synapses, which may be related to impaired intracellular transport of vesicular glutamate transporter 1 and brain-derived neurotrophic factor. The present findings extend our previous work and may help to better understand the pathogenesis of Fahr’s disease.
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Affiliation(s)
- Xin-Tai Wang
- Department of Physiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Lin Zhou
- Department of Physiology, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Psychiatry, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xin-Yu Cai
- Department of Physiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Fang-Xiao Xu
- Department of Physiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhi-Heng Xu
- State Key Laboratory of Molecular Developmental Biology, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xiang-Yao Li
- Department of Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Ying Shen
- Department of Physiology, School of Medicine, Zhejiang University, Hangzhou, China
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21
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A New Mouse Model Related to SCA14 Carrying a Pseudosubstrate Domain Mutation in PKCγ Shows Perturbed Purkinje Cell Maturation and Ataxic Motor Behavior. J Neurosci 2021; 41:2053-2068. [PMID: 33478986 PMCID: PMC7939089 DOI: 10.1523/jneurosci.1946-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 01/15/2023] Open
Abstract
Spinocerebellar ataxias (SCAs) are diseases characterized by cerebellar atrophy and loss of Purkinje neurons caused by mutations in diverse genes. In SCA14, the disease is caused by point mutations or small deletions in protein kinase C γ (PKCγ), a crucial signaling protein in Purkinje cells. It is still unclear whether increased or decreased PKCγ activity may be involved in the SCA14 pathogenesis. In this study, we present a new knock-in mouse model related to SCA14 with a point mutation in the pseudosubstrate domain, PKCγ-A24E, known to induce a constitutive PKCγ activation. In this protein conformation, the kinase domain of PKCγ is activated, but at the same time the protein is subject to dephosphorylation and protein degradation. As a result, we find a dramatic reduction of PKCγ protein expression in PKCγ-A24E mice of either sex. Despite this reduction, there is clear evidence for an increased PKC activity in Purkinje cells from PKCγ-A24E mice. Purkinje cells derived from PKCγ-A24E have short thickened dendrites typical for PKC activation. These mice also develop a marked ataxia and signs of Purkinje cell dysfunction making them an interesting new mouse model related to SCA. Recently, a similar mutation in a human patient was discovered and found to be associated with overt SCA14. RNA profiling of PKCγ-A24E mice showed a dysregulation of related signaling pathways, such as mGluR1 or mTOR. Our results show that the induction of PKCγ activation in Purkinje cells results in the SCA-like phenotype indicating PKC activation as one pathogenetic avenue leading to a SCA.SIGNIFICANCE STATEMENT Spinocerebellar ataxias (SCAs) are hereditary diseases affecting cerebellar Purkinje cells and are a one of neurodegenerative diseases. While mutation in several genes have been identified as causing SCAs, it is unclear how these mutations cause the disease phenotype. Mutations in PKCγ cause one subtype of SCAs, SCA14. In this study, we have generated a knock-in mouse with a mutation in the pseudosubstrate domain of PKCγ, which keeps PKCγ in the constitutive active open conformation. We show that this mutation leading to a constant activation of PKCγ results in a SCA-like phenotype in these mice. Our findings establish the constant activation of PKC signaling as one pathogenetic avenue leading to an SCA phenotype and a mechanism causing a neurodegenerative disease.
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22
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Refinement of Cerebellar Network Organization by Extracellular Signaling During Development. Neuroscience 2020; 462:44-55. [PMID: 32502568 DOI: 10.1016/j.neuroscience.2020.05.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/21/2022]
Abstract
The cerebellum forms regular neural network structures consisting of a few major types of neurons, such as Purkinje cells, granule cells, and molecular layer interneurons, and receives two major inputs from climbing fibers and mossy fibers. Its regular structures consist of three well-defined layers, with each type of neuron designated to a specific location and forming specific synaptic connections. During the first few weeks of postnatal development in rodents, the cerebellum goes through dynamic changes via proliferation, migration, differentiation, synaptogenesis, and maturation, to create such a network structure. The development of this organized network structure presumably relies on the communication between developing elements in the network, including not only individual neurons, but also their dendrites, axons, and synapses. Therefore, it is reasonable that extracellular signaling via synaptic transmission, secreted molecules, and cell adhesion molecules, plays important roles in cerebellar network development. Although it is not yet clear as to how overall cerebellar development is orchestrated, there is indeed accumulating lines of evidence that extracellular signaling acts toward the development of individual elements in the cerebellar networks. In this article, we introduce what we have learned from many studies regarding the extracellular signaling required for cerebellar network development, including our recent study suggesting the importance of unbiased synaptic inputs from parallel fibers.
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23
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Rai Y, Watanabe T, Matsuyama K, Sakimura K, Uesaka N, Kano M. Phospholipase C β3 is Required for Climbing Fiber Synapse Elimination in Aldolase C-positive Compartments of the Developing Mouse Cerebellum. Neuroscience 2020; 462:36-43. [PMID: 32360594 DOI: 10.1016/j.neuroscience.2020.04.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 12/17/2022]
Abstract
In the cerebellum of neonatal mice, multiple climbing fibers (CFs) form excitatory synapses on each Purkinje cell (PC). Only one CF is strengthened in each PC from postnatal day 3 (P3) to P7, whereas the other weaker CFs are eliminated progressively from ∼P7 to ∼P11 (early phase of CF elimination) and from ∼P12 to ∼P17 (late phase of CF elimination). Type 1 metabotropic glutamate receptor (mGluR1) triggers a canonical pathway in PCs for the late phase of CF elimination. Among downstream signaling molecules of mGluR1, phospholipase C β3 (PLCβ3) and β4 (PLCβ4) are expressed complementarily in PCs of aldolase C (Aldoc)-positive (+) and Aldoc-negative (-) cerebellar compartments, respectively. PLCβ4 is reported to mediate the late phase of CF elimination in the anterior half of the cerebellar vermis which corresponds to the Aldoc (-) region. However, roles of PLCβ3 and Aldoc in CF synapse elimination are unknown. Here, we investigated CF innervation of PCs in Aldoc-tdTomato knock-in mice that underwent lentivirus-mediated knockdown (KD) of PLCβ3 in PCs during postnatal development. By recording CF-mediated excitatory postsynaptic currents from PCs and immunostaining CF synaptic terminals, we found that significantly higher percentage of PCs with PLCβ3-KD remained multiply innervated by CFs in Aldoc (+) compartments after P12, which was accompanied by impaired elimination of somatic CF synapses and reduced dendritic CF translocation. In contrast, deletion of Aldoc had no effect on CF synapse elimination. These results suggest that PLCβ3 is required for the late phase of CF elimination in Aldoc (+) PCs.
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Affiliation(s)
- Yurie Rai
- Depertment of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takaki Watanabe
- Depertment of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; International Research Center for Neurointelligence (IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo 113-0033, Japan
| | - Kyoko Matsuyama
- Depertment of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Naofumi Uesaka
- Depertment of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; International Research Center for Neurointelligence (IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo 113-0033, Japan
| | - Masanobu Kano
- Depertment of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; International Research Center for Neurointelligence (IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo 113-0033, Japan.
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24
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Falck J, Bruns C, Hoffmann-Conaway S, Straub I, Plautz EJ, Orlando M, Munawar H, Rivalan M, Winter Y, Izsvák Z, Schmitz D, Hamra FK, Hallermann S, Garner CC, Ackermann F. Loss of Piccolo Function in Rats Induces Cerebellar Network Dysfunction and Pontocerebellar Hypoplasia Type 3-like Phenotypes. J Neurosci 2020; 40:2943-2959. [PMID: 32122952 PMCID: PMC7117892 DOI: 10.1523/jneurosci.2316-19.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/16/2022] Open
Abstract
Piccolo, a presynaptic active zone protein, is best known for its role in the regulated assembly and function of vertebrate synapses. Genetic studies suggest a further link to several psychiatric disorders as well as Pontocerebellar Hypoplasia type 3 (PCH3). We have characterized recently generated Piccolo KO (Pclogt/gt ) rats. Analysis of rats of both sexes revealed a dramatic reduction in brain size compared with WT (Pclowt/wt ) animals, attributed to a decrease in the size of the cerebral cortical, cerebellar, and pontine regions. Analysis of the cerebellum and brainstem revealed a reduced granule cell layer and a reduction in size of pontine nuclei. Moreover, the maturation of mossy fiber afferents from pontine neurons and the expression of the α6 GABAA receptor subunit at the mossy fiber-granule cell synapse are perturbed, as well as the innervation of Purkinje cells by cerebellar climbing fibers. Ultrastructural and functional studies revealed a reduced size of mossy fiber boutons, with fewer synaptic vesicles and altered synaptic transmission. These data imply that Piccolo is required for the normal development, maturation, and function of neuronal networks formed between the brainstem and cerebellum. Consistently, behavioral studies demonstrated that adult Pclogt/gt rats display impaired motor coordination, despite adequate performance in tasks that reflect muscle strength and locomotion. Together, these data suggest that loss of Piccolo function in patients with PCH3 could be involved in many of the observed anatomical and behavioral symptoms, and that the further analysis of these animals could provide fundamental mechanistic insights into this devastating disorder.SIGNIFICANCE STATEMENT Pontocerebellar Hypoplasia Type 3 is a devastating developmental disorder associated with severe developmental delay, progressive microcephaly with brachycephaly, optic atrophy, seizures, and hypertonia with hyperreflexia. Recent genetic studies have identified non-sense mutations in the coding region of the PCLO gene, suggesting a functional link between this disorder and the presynaptic active zone. Our analysis of Piccolo KO rats supports this hypothesis, formally demonstrating that anatomical and behavioral phenotypes seen in patients with Pontocerebellar Hypoplasia Type 3 are also exhibited by these Piccolo deficient animals.
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Affiliation(s)
- Joanne Falck
- German Center for Neurodegenerative Diseases, Charité Medical University, 10117 Berlin, Germany
| | - Christine Bruns
- German Center for Neurodegenerative Diseases, Charité Medical University, 10117 Berlin, Germany
| | - Sheila Hoffmann-Conaway
- German Center for Neurodegenerative Diseases, Charité Medical University, 10117 Berlin, Germany
| | - Isabelle Straub
- Carl-Ludwig Institute for Physiology, 04103 Leipzig, Germany
| | - Erik J Plautz
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, Texas 75390
| | - Marta Orlando
- Charité Medical University Berlin and Berlin Institute of Health, NeuroCure Cluster of Excellence, 10117 Berlin, Germany
| | - Humaira Munawar
- Department of Biology, Humboldt University, 10099 Berlin, Germany
| | - Marion Rivalan
- Charité Medical University Berlin and Berlin Institute of Health, NeuroCure Cluster of Excellence, 10117 Berlin, Germany
- Department of Biology, Humboldt University, 10099 Berlin, Germany
| | - York Winter
- Charité Medical University Berlin and Berlin Institute of Health, NeuroCure Cluster of Excellence, 10117 Berlin, Germany
- Department of Biology, Humboldt University, 10099 Berlin, Germany
| | - Zsuzsanna Izsvák
- Max Delbrück Center for Molecular Medicine in the Helmholtz Society, 13125 Berlin, Germany, and
| | - Dietmar Schmitz
- Charité Medical University Berlin and Berlin Institute of Health, NeuroCure Cluster of Excellence, 10117 Berlin, Germany
| | - F Kent Hamra
- Department of Obstetrics and Gynecology, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern, Dallas, Texas 75390
| | | | - Craig Curtis Garner
- German Center for Neurodegenerative Diseases, Charité Medical University, 10117 Berlin, Germany
| | - Frauke Ackermann
- German Center for Neurodegenerative Diseases, Charité Medical University, 10117 Berlin, Germany,
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25
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Zhang RS, Liakath-Ali K, Südhof TC. Latrophilin-2 and latrophilin-3 are redundantly essential for parallel-fiber synapse function in cerebellum. eLife 2020; 9:e54443. [PMID: 32202499 PMCID: PMC7089768 DOI: 10.7554/elife.54443] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 03/05/2020] [Indexed: 12/13/2022] Open
Abstract
Latrophilin-2 (Lphn2) and latrophilin-3 (Lphn3) are adhesion GPCRs that serve as postsynaptic recognition molecules in CA1 pyramidal neurons of the hippocampus, where they are localized to distinct dendritic domains and are essential for different sets of excitatory synapses. Here, we studied Lphn2 and Lphn3 in the cerebellum. We show that latrophilins are abundantly and differentially expressed in the cerebellar cortex. Using conditional KO mice, we demonstrate that the Lphn2/3 double-deletion but not the deletion of Lphn2 or Lphn3 alone suppresses parallel-fiber synapses and reduces parallel-fiber synaptic transmission by ~50% without altering release probability. Climbing-fiber synapses, conversely, were unaffected. Even though ~50% of total cerebellar Lphn3 protein is expressed in Bergmann glia, Lphn3 deletion from Bergmann glia did not detectably impair excitatory or inhibitory synaptic transmission. Our studies demonstrate that Lphn2 and Lphn3 are selectively but redundantly required in Purkinje cells for parallel-fiber synapses.
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Affiliation(s)
- Roger Shen Zhang
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Kif Liakath-Ali
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
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26
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Bowie E, Goetz SC. TTBK2 and primary cilia are essential for the connectivity and survival of cerebellar Purkinje neurons. eLife 2020; 9:51166. [PMID: 31934864 PMCID: PMC7028366 DOI: 10.7554/elife.51166] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 01/13/2020] [Indexed: 12/15/2022] Open
Abstract
Primary cilia are vital signaling organelles that extend from most types of cells, including neurons and glia. These structures are essential for development of many tissues and organs; however, their function in adult tissues, particularly neurons in the brain, remains largely unknown. Tau tubulin kinase 2 (TTBK2) is a critical regulator of ciliogenesis, and is also mutated in a hereditary neurodegenerative disorder, spinocerebellar ataxia type 11 (SCA11). Here, we show that conditional knockout of Ttbk2 in adult mice results in degenerative cerebellar phenotypes that recapitulate aspects of SCA11 including motor coordination deficits and defects to Purkinje cell (PC) integrity. We also find that the Ttbk2 conditional mutant mice quickly lose cilia throughout the brain. We show that conditional knockout of the key ciliary trafficking gene Ift88 in adult mice results in nearly identical cerebellar phenotypes to those of the Ttbk2 knockout, indicating that disruption of ciliary signaling is a key driver of these phenotypes. Our data suggest that primary cilia play an integral role in maintaining the function of PCs in the adult cerebellum and reveal novel insights into mechanisms involved in neurodegeneration.
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Affiliation(s)
- Emily Bowie
- University Program in Genetics and Genomics, Duke University, Durham, United States
| | - Sarah C Goetz
- Department of Pharmacology and Cancer Biology, Duke University, Durham, United States
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27
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Ohtsuki G. Modification of Synaptic-Input Clustering by Intrinsic Excitability Plasticity on Cerebellar Purkinje Cell Dendrites. J Neurosci 2020; 40:267-282. [PMID: 31754008 PMCID: PMC6948944 DOI: 10.1523/jneurosci.3211-18.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 10/08/2019] [Accepted: 10/24/2019] [Indexed: 02/06/2023] Open
Abstract
The role of dendrites in the integration of widespread synaptic activity has been studied in experiments and theories (Johnston et al., 1996; Magee, 2007). However, whether the conduction of synaptic currents from dendrites to the soma depends on excitability of those dendritic branches is unclear. How modulation of the branch excitability affects the conduction of synaptic inputs and their selection on dendrites is also elusive. Here, I performed simultaneous voltage-clamp recordings from the soma and dendrites of single cerebellar Purkinje neurons in male Sprague-Dawley rats and analyzed the relationship between spontaneous EPSCs on both sides. I found that EPSCs on distal dendrites have a salient discordance in amplitude compared with those on the soma. Furthermore, individual ratios of the EPSC concurrently recorded on the soma and dendrites were not unique, but discrete, suggesting the occurrence of various attenuations in different paths of dendritic branches to the soma. The obtained data and simulations indicate several distinct groups (4.5 ± 0.3, n = 22 somatodendritic recordings) of co-occurred synaptic inputs in Purkinje cell dendrites. This clustering of synaptic currents was suggested to emerge at farther distances than the secondary bifurcations. Finally, ratios of the co-EPSCs were uniformly distributed after either intrinsic plasticity induction or SK-channel blockade. Overall, results suggest that in Purkinje cells the excitability along the dendrite processes modulates the conduction of EPSCs and makes active inputs heterogeneous through SK channel activity, intrinsic plasticity, and dendritic branching. These properties of dendrites may confer branch-specific computational power to neurons.SIGNIFICANCE STATEMENT I have previously studied the "non-synaptic" plasticity of the intrinsic excitability in the cerebellar Purkinje cells (Belmeguenai et al., 2010), and branch-specific increase of intrinsic excitability of the dendrites (Ohtsuki et al., 2012b; Ohtsuki and Hansel, 2018) through the downregulation of SK (small conductance Ca2+-activated K+) channels. In this study, I show that a dendritic filtering of synaptic electroconductivity is heterogeneous among the branches on distal dendrites and that the increase in the dendritic excitability accompanied with the intrinsic plasticity alters a state with the heterogeneity to a globally excitable state in Purkinje neurons. My findings propose a new learning model relying on the intrinsic excitability plasticity of the dendritic branch fields.
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Affiliation(s)
- Gen Ohtsuki
- The Hakubi Center for Advanced Research, Kyoto University, Yoshida, Sakyo-ward, Kyoto 606-8501, Japan, and
- Department of Biophysics, Kyoto University Graduate School of Science, Kitashirakawa-Oiwake-cho, Sakyo-ward, Kyoto 606-8224, Japan
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28
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Kana V, Desland FA, Casanova-Acebes M, Ayata P, Badimon A, Nabel E, Yamamuro K, Sneeboer M, Tan IL, Flanigan ME, Rose SA, Chang C, Leader A, Le Bourhis H, Sweet ES, Tung N, Wroblewska A, Lavin Y, See P, Baccarini A, Ginhoux F, Chitu V, Stanley ER, Russo SJ, Yue Z, Brown BD, Joyner AL, De Witte LD, Morishita H, Schaefer A, Merad M. CSF-1 controls cerebellar microglia and is required for motor function and social interaction. J Exp Med 2019; 216:2265-2281. [PMID: 31350310 PMCID: PMC6781012 DOI: 10.1084/jem.20182037] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 04/04/2019] [Accepted: 06/14/2019] [Indexed: 12/24/2022] Open
Abstract
Microglia, the brain resident macrophages, critically shape forebrain neuronal circuits. However, their precise function in the cerebellum is unknown. Here we show that human and mouse cerebellar microglia express a unique molecular program distinct from forebrain microglia. Cerebellar microglial identity was driven by the CSF-1R ligand CSF-1, independently of the alternate CSF-1R ligand, IL-34. Accordingly, CSF-1 depletion from Nestin+ cells led to severe depletion and transcriptional alterations of cerebellar microglia, while microglia in the forebrain remained intact. Strikingly, CSF-1 deficiency and alteration of cerebellar microglia were associated with reduced Purkinje cells, altered neuronal function, and defects in motor learning and social novelty interactions. These findings reveal a novel CSF-1-CSF-1R signaling-mediated mechanism that contributes to motor function and social behavior.
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Affiliation(s)
- Veronika Kana
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Fiona A Desland
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Maria Casanova-Acebes
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Pinar Ayata
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Ana Badimon
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Elisa Nabel
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY.,Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Kazuhiko Yamamuro
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY.,Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Marjolein Sneeboer
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - I-Li Tan
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY
| | - Meghan E Flanigan
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Samuel A Rose
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Christie Chang
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Andrew Leader
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Hortense Le Bourhis
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Eric S Sweet
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Navpreet Tung
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Aleksandra Wroblewska
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Yonit Lavin
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY.,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Peter See
- Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Alessia Baccarini
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Florent Ginhoux
- Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Violeta Chitu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
| | - E Richard Stanley
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Scott J Russo
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Zhenyu Yue
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Brian D Brown
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Alexandra L Joyner
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY
| | - Lotje D De Witte
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Hirofumi Morishita
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY.,Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY.,Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Anne Schaefer
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Miriam Merad
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY .,Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY.,Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
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29
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Park H, Kim T, Kim J, Yamamoto Y, Tanaka-Yamamoto K. Inputs from Sequentially Developed Parallel Fibers Are Required for Cerebellar Organization. Cell Rep 2019; 28:2939-2954.e5. [DOI: 10.1016/j.celrep.2019.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/10/2019] [Accepted: 07/30/2019] [Indexed: 11/15/2022] Open
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30
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Abstract
Functional neural circuits of mature animals are shaped during postnatal development by eliminating early-formed redundant synapses and strengthening of necessary connections. In the nervous system of newborn animals, redundant synapses are only transient features of the circuit. During subsequent postnatal development, some synapses are strengthened whereas other redundant connections are weakened and eventually eliminated. In this review, we introduce recent studies on the mechanisms of developmental remodeling of climbing fiber-to-Purkinje cell synapses in the cerebellum and synapses from the retina to neurons in the dorsal lateral geniculate nucleus of the visual thalamus (retinogeniculate synapses). These are the two representative models of developmental synapse remodeling in the brain and they share basic principles, including dependency on neural activity. However, recent studies have disclosed that, in several respects, the two models use different molecules and strategies to establish mature synaptic connectivity. We describe similarities and differences between the two models and discuss remaining issues to be tackled in the future in order to understand the general schemes of developmental synapse remodeling.
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Affiliation(s)
- Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.,International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takaki Watanabe
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.,International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, 113-0033, Japan
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31
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Cha HL, Choi JM, Oh HH, Bashyal N, Kim SS, Birnbaumer L, Suh-Kim H. Deletion of the α subunit of the heterotrimeric Go protein impairs cerebellar cortical development in mice. Mol Brain 2019; 12:57. [PMID: 31221179 PMCID: PMC6585000 DOI: 10.1186/s13041-019-0477-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/29/2019] [Indexed: 02/02/2023] Open
Abstract
Go is a member of the pertussis toxin-sensitive Gi/o family. Despite its abundance in the central nervous system, the precise role of Go remains largely unknown compared to other G proteins. In the present study, we explored the functions of Go in the developing cerebellar cortex by deleting its gene, Gnao. We performed a histological analysis with cerebellar sections of adult mice by cresyl violet- and immunostaining. Global deletion of Gnao induced cerebellar hypoplasia, reduced arborization of Purkinje cell dendrites, and atrophied Purkinje cell dendritic spines and the terminal boutons of climbing fibers from the inferior olivary nucleus. These results indicate that Go-mediated signaling pathway regulates maturation of presynaptic parallel fibers from granule cells and climbing fibers during the cerebellar cortical development.
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Affiliation(s)
- Hye Lim Cha
- Departments of Anatomy, Ajou University School of Medicine, Woldcup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
| | - Jung-Mi Choi
- Departments of Anatomy, Ajou University School of Medicine, Woldcup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
| | - Huy-Hyen Oh
- Departments of Anatomy, Ajou University School of Medicine, Woldcup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
| | - Narayan Bashyal
- Departments of Anatomy, Ajou University School of Medicine, Woldcup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
- Departments of Biomedical Sciences, The Graduate School, Ajou University School of Medicine, World cup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
| | - Sung-Soo Kim
- Departments of Anatomy, Ajou University School of Medicine, Woldcup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, 27709 NC USA
- Institute of Biomedical Research (BIOMED), School of Medical Sciences, Catholic University of Argentina, Av. Alicia Moreau de Justo 1300, Edificio San Jose Piso 3, C1107AAZ Buenos Aires, Argentina
| | - Haeyoung Suh-Kim
- Departments of Anatomy, Ajou University School of Medicine, Woldcup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
- Departments of Biomedical Sciences, The Graduate School, Ajou University School of Medicine, World cup-ro 164, Yeongtong-gu, Suwon, 16499 South Korea
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32
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Toledo A, Lang F, Doengi M, Morrison H, Stein V, Baader SL. Merlin modulates process outgrowth and synaptogenesis in the cerebellum. Brain Struct Funct 2019; 224:2121-2142. [PMID: 31165301 DOI: 10.1007/s00429-019-01897-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 05/29/2019] [Indexed: 12/14/2022]
Abstract
Neurofibromatosis type 2 (NF2) patients are prone to develop glial-derived tumors in the peripheral and central nervous system (CNS). The Nf2 gene product -Merlin is not only expressed in glia, but also in neurons of the CNS, where its function still remains elusive. Here, we show that cerebellar Purkinje cells (PCs) of isoform-specific Merlin-deficient mice were innervated by smaller vGluT2-positive clusters at presynaptic terminals than those of wild-type mice. This was paralleled by a reduction in frequency and amplitude of miniature excitatory postsynaptic currents (mEPSC). On the contrary, in conditional transgenic mice in which Merlin expression was specifically ablated in PCs (L7Cre;Nf2fl/fl), we found enlarged vGluT2-positive clusters in their presynaptic buttons together with increased amplitudes of miniature postsynaptic currents. The presynaptic terminals of these PCs innervating neurons of the deep cerebellar nuclei were also enlarged. When exploring mice with Merlin-deficient granule cells (GCs) (Math1Cre;Nf2fl/fl), we found cerebellar extracts to contain higher amounts of vGluT1 present in parallel fiber terminals. In parallel, mEPSC frequency was increased in Math1Cre;Nf2fl/fl mice. On the contrary, VGluT2 clusters in cerebellar glomeruli composed of NF2-deficient presynaptic Mossy fiber terminals and NF2-deficient postsynaptic GC were reduced in size as shown for isoform-specific knockout mice. These changes in Math1Cre;Nf2fl/fl-deficient mice were paralleled by an increased activation of Rac1-Cofilin signaling which is known to impact on cytoskeletal reorganization and synapse formation. Consistent with the observed synaptic alterations in these transgenic mice, we observed altered ultrasonic vocalization, which is known to rely on proper cerebellar function. No gross morphological changes or motor coordination deficits were observed in any of these transgenic mice. We therefore conclude that Merlin does not regulate overall cerebellar development, but impacts on pre- and post-synaptic terminal organization.
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Affiliation(s)
- A Toledo
- Institute of Anatomy, Anatomy and Cell Biology, Bonn University, 53115, Bonn, Germany
| | - F Lang
- Institute of Anatomy, Anatomy and Cell Biology, Bonn University, 53115, Bonn, Germany
| | - M Doengi
- Institute of Physiology II, Bonn University, 53115, Bonn, Germany
| | - H Morrison
- Leibniz Institute for Age Research, Fritz Lipmann Institute, 07745, Jena, Germany
| | - V Stein
- Institute of Physiology II, Bonn University, 53115, Bonn, Germany
| | - S L Baader
- Institute of Anatomy, Anatomy and Cell Biology, Bonn University, 53115, Bonn, Germany.
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Kamath SP, Chen AI. Myocyte Enhancer Factor 2c Regulates Dendritic Complexity and Connectivity of Cerebellar Purkinje Cells. Mol Neurobiol 2018; 56:4102-4119. [PMID: 30276662 PMCID: PMC6505522 DOI: 10.1007/s12035-018-1363-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/21/2018] [Indexed: 12/05/2022]
Abstract
Mef2c haploinsufficiency is implicated in behavioral deficits related to autism, schizophrenia, and intellectual disability. Although perturbations in the cerebellum, notably Purkinje cells, have been linked to these neurological disorders, the underlying mechanisms remain poorly understood. In this study, we investigated the roles of Mef2c in cerebellar Purkinje cells during the first three weeks of postnatal development. Our analysis revealed that in comparison to other members of the Mef2 family, Mef2c expression is limited to postnatal Purkinje cells. Because the role of Mef2c has not been assessed in GABAergic neurons, we set out to determine the functional significance of Mef2c by knocking down the expression of Mef2c selectively in Purkinje cells. We found that the loss of Mef2c expression during the first and second postnatal week results in an increase in dendritic arborization without impact on the general growth and migration of Purkinje cells. The influence of Mef2c on dendritic arborization persists throughout the first three weeks, but is most prominent during the first postnatal week suggesting a critical period of Mef2c activity. Additionally, the loss of Mef2c expression results in an increase in the number of spines accompanied by an increase in Gad67 and vGluT1 puncta and decrease in vGluT2 puncta. Thus, our results reveal the specific expression and functional relevance of Mef2c in developing Purkinje cells and offer insight to how disruption of the expression of Mef2c in a GABAergic neuronal subtype may lead to pathogenesis of cerebellar-associated disorders.
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Affiliation(s)
- Sandhya Prakash Kamath
- School of Biological Sciences, Nanyang Technological University (NTU), Singapore, 637551, Singapore
| | - Albert I Chen
- School of Biological Sciences, Nanyang Technological University (NTU), Singapore, 637551, Singapore.
- A*STAR, Institute of Molecular and Cell Biology, Singapore, 138673, Singapore.
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
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mGlu1 Receptors Monopolize the Synaptic Control of Cerebellar Purkinje Cells by Epigenetically Down-Regulating mGlu5 Receptors. Sci Rep 2018; 8:13361. [PMID: 30190524 PMCID: PMC6127335 DOI: 10.1038/s41598-018-31369-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/09/2018] [Indexed: 11/10/2022] Open
Abstract
In cerebellar Purkinje cells (PCs) type-1 metabotropic glutamate (mGlu1) receptors play a key role in motor learning and drive the refinement of synaptic innervation during postnatal development. The cognate mGlu5 receptor is absent in mature PCs and shows low expression levels in the adult cerebellar cortex. Here we found that mGlu5 receptors were heavily expressed by PCs in the early postnatal life, when mGlu1α receptors were barely detectable. The developmental decline of mGlu5 receptors coincided with the appearance of mGlu1α receptors in PCs, and both processes were associated with specular changes in CpG methylation in the corresponding gene promoters. It was the mGlu1 receptor that drove the elimination of mGlu5 receptors from PCs, as shown by data obtained with conditional mGlu1α receptor knockout mice and with targeted pharmacological treatments during critical developmental time windows. The suppressing activity of mGlu1 receptors on mGlu5 receptor was maintained in mature PCs, suggesting that expression of mGlu1α and mGlu5 receptors is mutually exclusive in PCs. These findings add complexity to the the finely tuned mechanisms that regulate PC biology during development and in the adult life and lay the groundwork for an in-depth analysis of the role played by mGlu5 receptors in PC maturation.
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35
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Kikuchihara S, Sugio S, Tanaka KF, Watanabe T, Kano M, Yamazaki Y, Watanabe M, Ikenaka K. Ectopic positioning of Bergmann glia and impaired cerebellar wiring in Mlc1-over-expressing mice. J Neurochem 2018; 147:344-360. [PMID: 29920672 DOI: 10.1111/jnc.14486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 03/25/2018] [Accepted: 04/30/2018] [Indexed: 11/28/2022]
Abstract
Mlc1 is a causative gene for megalencephalic leukoencephalopathy with subcortical cysts, and is expressed in astrocytes. Mlc1-over-expressing mice represent an animal model of early-onset leukoencephalopathy, which manifests as astrocytic swelling followed by myelin membrane splitting in the white matter. It has been previously reported that Mlc1 is highly expressed in Bergmann glia, while the cerebellar phenotypes of Mlc1-over-expressing mouse have not been characterized. Here, we examined the cerebellum of Mlc1-over-expressing mouse and found that the distribution of Bergmann glia (BG) was normally compacted along the Purkinje cell (PC) layer until postnatal day 10 (P10), while most BG were dispersed throughout the molecular layer by P28. Ectopic BG were poorly wrapped around somatodendritic elements of PCs and exhibited reduced expression of the glutamate transporter glutamate-aspartate transporter. Extraordinarily slow and small climbing fiber (CF)-mediated excitatory post-synaptic currents, which are known to be elicited under accelerated glutamate spillover, emerged at P20-P28 when BG ectopia was severe, but not at P9-P12 when ectopia was mild. Furthermore, maturation of CF wiring, which translocates the site of innervation from somata to proximal dendrites, was also impaired. Manipulations that restricted the Mlc1-over-expressing period successfully generated mice with and without BG ectopia, depending on the over-expressing period. Together, these findings suggest that there is a critical time window for mechanisms that promote the positioning of BG in the PC layer. Once normal positioning of BG is affected, the differentiation of BG is impaired, leading to insufficient glial wrapping, exacerbated glutamate spillover, and aberrant synaptic wiring in PCs. Open Practices Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/ Cover Image for this issue: doi: 10.1111/jnc.14199.
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Affiliation(s)
- Saori Kikuchihara
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan.,Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan
| | - Shouta Sugio
- Department of Molecular and Cellular Neurobiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Takaki Watanabe
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshihiko Yamazaki
- Department of Physiology, Yamagata University School of Medicine, Yamagata, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Kazuhiro Ikenaka
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan.,Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan
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Nakayama H, Abe M, Morimoto C, Iida T, Okabe S, Sakimura K, Hashimoto K. Microglia permit climbing fiber elimination by promoting GABAergic inhibition in the developing cerebellum. Nat Commun 2018; 9:2830. [PMID: 30026565 PMCID: PMC6053401 DOI: 10.1038/s41467-018-05100-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/23/2018] [Indexed: 01/01/2023] Open
Abstract
Circuit refinement during postnatal development is finely regulated by neuron–neuron interactions. Recent studies suggest participation of microglia in this process but it is unclear how microglia cooperatively act with neuronal mechanisms. To examine roles of microglia, we ablate microglia by microglia-selective deletion of colony-stimulating factor 1 receptor (Csf1r) by crossing floxed-Csf1r and Iba1-iCre mice (Csf1r-cKO). In Csf1r-cKO mice, refinement of climbing fiber (CF) to Purkinje cell (PC) innervation after postnatal day 10 (P10)–P12 is severely impaired. However, there is no clear morphological evidence suggesting massive engulfment of CFs by microglia. In Csf1r-cKO mice, inhibitory synaptic transmission is impaired and CF elimination is restored by diazepam, which suggests that impairment of CF elimination is caused by a defect of GABAergic inhibition on PCs, a prerequisite for CF elimination. These results indicate that microglia primarily promote GABAergic inhibition and secondarily facilitate the mechanism for CF elimination inherent in PCs. In the mammalian cerebellum, surplus synapses between climbing fibers (CF) and Purkinje cells (PC) are developmentally pruned. Here, Nakayama and colleagues show that ablation of microglia impairs pruning of CF-PC synapses because of dysfunction of GABAergic inhibition prerequisite for pruning.
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Affiliation(s)
- Hisako Nakayama
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.,Department of Physiology, School of Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Sinjuku-ku, Tokyo, 162-8666, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8585, Japan.,Department of Animal Model Development, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8585, Japan
| | - Chie Morimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.,Department of Psychosocial Rehabilitation Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Tadatsune Iida
- Department of Cellular Neurobiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8585, Japan.,Department of Animal Model Development, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8585, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
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37
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Kano M, Watanabe T, Uesaka N, Watanabe M. Multiple Phases of Climbing Fiber Synapse Elimination in the Developing Cerebellum. THE CEREBELLUM 2018; 17:722-734. [DOI: 10.1007/s12311-018-0964-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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38
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Helleringer R, Le Verger D, Li X, Izabelle C, Chaussenot R, Belmaati-Cherkaoui M, Dammak R, Decottignies P, Daniel H, Galante M, Vaillend C. Cerebellar synapse properties and cerebellum-dependent motor and non-motor performance in Dp71-null mice. Dis Model Mech 2018; 11:dmm.033258. [PMID: 29895670 PMCID: PMC6078407 DOI: 10.1242/dmm.033258] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 06/04/2018] [Indexed: 02/04/2023] Open
Abstract
Recent emphasis has been placed on the role that cerebellar dysfunctions could have in the genesis of cognitive deficits in Duchenne muscular dystrophy (DMD). However, relevant genotype-phenotype analyses are missing to define whether cerebellar defects underlie the severe cases of intellectual deficiency that have been associated with genetic loss of the smallest product of the dmd gene, the Dp71 dystrophin. To determine for the first time whether Dp71 loss could affect cerebellar physiology and functions, we have used patch-clamp electrophysiological recordings in acute cerebellar slices and a cerebellum-dependent behavioral test battery addressing cerebellum-dependent motor and non-motor functions in Dp71-null transgenic mice. We found that Dp71 deficiency selectively enhances excitatory transmission at glutamatergic synapses formed by climbing fibers (CFs) on Purkinje neurons, but not at those formed by parallel fibers. Altered basal neurotransmission at CFs was associated with impairments in synaptic plasticity and clustering of the scaffolding postsynaptic density protein PSD-95. At the behavioral level, Dp71-null mice showed some improvements in motor coordination and were unimpaired for muscle force, static and dynamic equilibrium, motivation in high-motor demand and synchronization learning. Dp71-null mice displayed altered strategies in goal-oriented navigation tasks, however, suggesting a deficit in the cerebellum-dependent processing of the procedural components of spatial learning, which could contribute to the visuospatial deficits identified in this model. In all, the observed deficits suggest that Dp71 loss alters cerebellar synapse function and cerebellum-dependent navigation strategies without being detrimental for motor functions. Summary: Dp71 is the most prominent dystrophin gene product in the adult brain. Here, multiple approaches including behavioral tests and electrophysiology are adopted to explore the role of Dp71 in the cerebellum.
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Affiliation(s)
- Romain Helleringer
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Delphine Le Verger
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Xia Li
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Charlotte Izabelle
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Rémi Chaussenot
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Mehdi Belmaati-Cherkaoui
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Raoudha Dammak
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Paulette Decottignies
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Hervé Daniel
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Micaela Galante
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Cyrille Vaillend
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
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39
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Bailly Y, Rabacchi S, Sherrard RM, Rodeau JL, Demais V, Lohof AM, Mariani J. Elimination of all redundant climbing fiber synapses requires granule cells in the postnatal cerebellum. Sci Rep 2018; 8:10017. [PMID: 29968809 PMCID: PMC6030189 DOI: 10.1038/s41598-018-28398-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 06/21/2018] [Indexed: 11/20/2022] Open
Abstract
Different afferent synapse populations interact to control the specificity of connections during neuronal circuit maturation. The elimination of all but one climbing-fiber onto each Purkinje cell during the development of the cerebellar cortex is a particularly well studied example of synaptic refinement. The suppression of granule cell precursors by X irradiation during postnatal days 4 to 7 prevents this synaptic refinement, indicating a critical role for granule cells. Several studies of cerebellar development have suggested that synapse elimination has a first phase which is granule cell-independent and a second phase which is granule cell-dependent. In this study, we show that sufficiently-strong irradiation restricted to postnatal days 5 or 6 completely abolishes climbing fiber synaptic refinement, leaving the olivo-cerebellar circuit in its immature configuration in the adult, with up to 5 climbing fibers innervating the Purkinje cell in some cases. This implies that the putative early phase of climbing fiber synapse elimination can be blocked by irradiation-induced granule cell loss if this loss is sufficiently large, and thus indicates that the entire process of climbing fiber synapse elimination requires the presence of an adequate number of granule cells. The specific critical period for this effect appears to be directly related to the timing of Purkinje cell and granule cell development in different cerebellar lobules, indicating a close, spatiotemporal synchrony between granule-cell development and olivo-cerebellar synaptic maturation.
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Affiliation(s)
- Yannick Bailly
- Intracellular Membrane Trafficking in the Nervous and Neuroendocrine System, INCI, CNRS UPR3212, Universite de Strasbourg, Strasbourg, France.
| | - Sylvia Rabacchi
- Sorbonne Université, CNRS UMR 8256, Biological Adaptation and Ageing, B2A, 75005, Paris, France
- BiogenIdec, Inc., Cambridge, Massachusetts, 02140, USA
| | - Rachel M Sherrard
- Sorbonne Université, CNRS UMR 8256, Biological Adaptation and Ageing, B2A, 75005, Paris, France
- APHP, DHU FAST, Institut de la longévité, 94205, Ivry-Sur-Seine, France
| | - Jean-Luc Rodeau
- Nociceptive Signalling in the Spinal Cord, CNRS UPR3212, Universite de Strasbourg, Strasbourg, France
| | - Valérie Demais
- Intracellular Membrane Trafficking in the Nervous and Neuroendocrine System, INCI, CNRS UPR3212, Universite de Strasbourg, Strasbourg, France
- Plateforme d'Imagerie In vitro, CNRS UPS 3156 Universite de Strasbourg, Strasbourg, France
| | - Ann M Lohof
- Sorbonne Université, CNRS UMR 8256, Biological Adaptation and Ageing, B2A, 75005, Paris, France
| | - Jean Mariani
- Sorbonne Université, CNRS UMR 8256, Biological Adaptation and Ageing, B2A, 75005, Paris, France.
- APHP, DHU FAST, Institut de la longévité, 94205, Ivry-Sur-Seine, France.
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40
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Uesaka N, Abe M, Konno K, Yamazaki M, Sakoori K, Watanabe T, Kao TH, Mikuni T, Watanabe M, Sakimura K, Kano M. Retrograde Signaling from Progranulin to Sort1 Counteracts Synapse Elimination in the Developing Cerebellum. Neuron 2018; 97:796-805.e5. [DOI: 10.1016/j.neuron.2018.01.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/07/2017] [Accepted: 01/08/2018] [Indexed: 12/22/2022]
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41
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Hoxha E, Lippiello P, Scelfo B, Tempia F, Ghirardi M, Miniaci MC. Maturation, Refinement, and Serotonergic Modulation of Cerebellar Cortical Circuits in Normal Development and in Murine Models of Autism. Neural Plast 2017; 2017:6595740. [PMID: 28894610 PMCID: PMC5574313 DOI: 10.1155/2017/6595740] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/06/2017] [Accepted: 07/25/2017] [Indexed: 12/13/2022] Open
Abstract
The formation of the complex cerebellar cortical circuits follows different phases, with initial synaptogenesis and subsequent processes of refinement guided by a variety of mechanisms. The regularity of the cellular and synaptic organization of the cerebellar cortex allowed detailed studies of the structural plasticity mechanisms underlying the formation of new synapses and retraction of redundant ones. For the attainment of the monoinnervation of the Purkinje cell by a single climbing fiber, several signals are involved, including electrical activity, contact signals, homosynaptic and heterosynaptic interaction, calcium transients, postsynaptic receptors, and transduction pathways. An important role in this developmental program is played by serotonergic projections that, acting on temporally and spatially regulated postsynaptic receptors, induce and modulate the phases of synaptic formation and maturation. In the adult cerebellar cortex, many developmental mechanisms persist but play different roles, such as supporting synaptic plasticity during learning and formation of cerebellar memory traces. A dysfunction at any stage of this process can lead to disorders of cerebellar origin, which include autism spectrum disorders but are not limited to motor deficits. Recent evidence in animal models links impairment of Purkinje cell function with autism-like symptoms including sociability deficits, stereotyped movements, and interspecific communication by vocalization.
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Affiliation(s)
- Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
- Department of Neuroscience, University of Torino, Torino, Italy
| | | | - Bibiana Scelfo
- Department of Neuroscience, University of Torino, Torino, Italy
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
- Department of Neuroscience, University of Torino, Torino, Italy
- National Institute of Neuroscience (INN), Torino, Italy
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Choo M, Miyazaki T, Yamazaki M, Kawamura M, Nakazawa T, Zhang J, Tanimura A, Uesaka N, Watanabe M, Sakimura K, Kano M. Retrograde BDNF to TrkB signaling promotes synapse elimination in the developing cerebellum. Nat Commun 2017; 8:195. [PMID: 28775326 PMCID: PMC5543168 DOI: 10.1038/s41467-017-00260-w] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 06/14/2017] [Indexed: 12/31/2022] Open
Abstract
Elimination of early-formed redundant synapses during postnatal development is essential for functional neural circuit formation. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs). A single CF is strengthened whereas the other CFs are eliminated in each PC dependent on postsynaptic activity in PC, but the underlying mechanisms are largely unknown. Here, we report that brain-derived neurotrophic factor (BDNF) from PC facilitates CF synapse elimination. By PC-specific deletion of BDNF combined with knockdown of BDNF receptors in CF, we show that BDNF acts retrogradely on TrkB in CFs, and facilitates elimination of CF synapses from PC somata during the third postnatal week. We also show that BDNF shares signaling pathway with metabotropic glutamate receptor 1, a key molecule that triggers a canonical pathway for CF synapse elimination. These results indicate that unlike other synapses, BDNF mediates punishment signal for synapse elimination in the developing cerebellum. During development, synapses are selectively strengthened or eliminated by activity-dependent competition. Here, the authors show that BDNF-TrkB retrograde signaling is a “punishment” signal that leads to elimination of climbing fiber-onto-Purkinje cell synapses in the developing cerebellum.
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Affiliation(s)
- Myeongjeong Choo
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Taisuke Miyazaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Meiko Kawamura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Takanobu Nakazawa
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Jianling Zhang
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Asami Tanimura
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Naofumi Uesaka
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.
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Narushima M. Comparison of the role of metabotropic glutamate receptor subtype 1 in developmental refinement of neuronal connectivity between the cerebellum and the sensory thalamus. Neurosci Res 2017; 129:24-31. [PMID: 28711710 DOI: 10.1016/j.neures.2017.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/15/2017] [Accepted: 06/15/2017] [Indexed: 11/30/2022]
Abstract
Developmental refinement of neuronal connectivity is crucial for proper brain function. In the early phase of development, input fibers arrive at their target areas guided by specific molecular cues and form abundant immature synapses. Then, functionally important synapses are preserved and strengthened by neural activity while unnecessary synapses are eliminated. Afferent synapses in the sensory thalamus, such as from retina to lateral geniculate nucleus, and climbing fiber (CF)-Purkinje cell (PC) synapses in the cerebellum are valuable models for studying this developmental refinement of synaptic connectivity because only a limited number of input fibers innervate a given postsynaptic thalamocortical (TC) neuron or PC. The metabotropic glutamate receptor subtype 1 (mGluR1) is required for the refinement of both afferent-TC neuron and CF-PC synapses. However, mGluR1 functions differently at these synapses. While mGluR1 is critical for elimination of surplus CF-PC synapses in the cerebellum, retinogeniculate synapses require mGluR1 for maintenance of mature connectivity.
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Affiliation(s)
- Madoka Narushima
- Department of Physiology (I), School of Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
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Miyazaki T, Yamasaki M, Hashimoto K, Kohda K, Yuzaki M, Shimamoto K, Tanaka K, Kano M, Watanabe M. Glutamate transporter GLAST controls synaptic wrapping by Bergmann glia and ensures proper wiring of Purkinje cells. Proc Natl Acad Sci U S A 2017; 114:7438-7443. [PMID: 28655840 PMCID: PMC5514701 DOI: 10.1073/pnas.1617330114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Astrocytes regulate synaptic transmission through controlling neurotransmitter concentrations around synapses. Little is known, however, about their roles in neural circuit development. Here we report that Bergmann glia (BG), specialized cerebellar astrocytes that thoroughly enwrap Purkinje cells (PCs), are essential for synaptic organization in PCs through the action of the l-glutamate/l-aspartate transporter (GLAST). In GLAST-knockout mice, dendritic innervation by the main ascending climbing fiber (CF) branch was significantly weakened, whereas the transverse branch, which is thin and nonsynaptogenic in control mice, was transformed into thick and synaptogenic branches. Both types of CF branches frequently produced aberrant wiring to proximal and distal dendrites, causing multiple CF-PC innervation. Our electrophysiological analysis revealed that slow and small CF-evoked excitatory postsynaptic currents (EPSCs) were recorded from almost all PCs in GLAST-knockout mice. These atypical CF-EPSCs were far more numerous and had significantly faster 10-90% rise time than those elicited by glutamate spillover under pharmacological blockade of glial glutamate transporters. Innervation by parallel fibers (PFs) was also affected. PF synapses were robustly increased in the entire dendritic trees, leading to impaired segregation of CF and PF territories. Furthermore, lamellate BG processes were retracted from PC dendrites and synapses, leading to the exposure of these neuronal elements to the extracellular milieus. These synaptic and glial phenotypes were reproduced in wild-type mice after functional blockade of glial glutamate transporters. These findings highlight that glutamate transporter function by GLAST on BG plays important roles in development and maintenance of proper synaptic wiring and wrapping in PCs.
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Affiliation(s)
- Taisuke Miyazaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Miwako Yamasaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Kazuhisa Kohda
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Department of Physiology, St. Marianna University School of Medicine, Kanagawa 216-8511, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Keiko Shimamoto
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, 619-0284, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan;
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GluD2 Endows Parallel Fiber-Purkinje Cell Synapses with a High Regenerative Capacity. J Neurosci 2017; 36:4846-58. [PMID: 27122040 DOI: 10.1523/jneurosci.0161-16.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/22/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Although injured axons usually do not regenerate in the adult CNS, parallel fibers (PFs) regenerate synaptic connections onto cerebellar Purkinje cells (PCs). In this study, we investigated the role of GluD2 in this regenerative process after PF transection using GluD2-knock-out (KO) mice. All dendritic spines on distal dendrites were innervated by PFs in sham-operated wild-type controls, whereas one-third were devoid of innervation in GluD2-KO mice. In both genotypes, a steep drop in the number of PF synapses occurred with a reciprocal surge in the number of free spines on postlesion day 1, when the PF territory aberrantly expanded toward the proximal dendrites. In wild-type mice, the territory and number of PF synapses were nearly fully restored to normal on postlesion day 7, although PF density remained low. Moreover, presynaptic and postsynaptic elements were markedly enlarged, and the PF terminal-to-PC spine contact ratio increased from 1:1 to 1:2 at most synapses. On postlesion day 30, the size and contact ratio of PF synapses returned to sham-operated control values and PF density recovered through the sprouting and elongation of PF collaterals. However, GluD2-KO mice showed neither a hypertrophic response nor territorial restoration 7 d postlesion, nor the recovery of PF axons or synapses on postlesion day 30. This suggests that PF wiring regenerates initially by inducing hypertrophic responses in surviving synaptic elements (hypertrophic phase), followed by collateral formation by PF axons and retraction of PF synapses (remodeling phase). Without GluD2, no transition to these regenerative phases occurs. SIGNIFICANCE STATEMENT The glutamate receptor GluD2 expressed at parallel fiber (PF)-Purkinje cell (PC) synapses regulates the formation and maintenance of the synapses. To investigate the role of GluD2 in their extraordinarily high regenerative capacity, the process after surgical transection of PFs was compared between wild-type and GluD2-knock-out mice. We discovered that, in wild-type mice, PF synapses regenerate initially by inducing hypertrophic responses in surviving synaptic elements, and then by sprouting and elongation of PF collaterals. Subsequently, hypertrophied PF synapses remodel into compact synapses. In GluD2-knock-out mice, PF wiring remains in the degenerative phase, showing neither a hypertrophic response nor recovery of PF axons or synapses. Our finding thus highlights that synaptic connection in the adult brain can regenerate with aid of GluD2.
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Kano M, Watanabe T. Type-1 metabotropic glutamate receptor signaling in cerebellar Purkinje cells in health and disease. F1000Res 2017; 6:416. [PMID: 28435670 PMCID: PMC5381626 DOI: 10.12688/f1000research.10485.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/30/2017] [Indexed: 01/28/2023] Open
Abstract
The cerebellum is a brain structure involved in coordination, control, and learning of movements, as well as certain aspects of cognitive function. Purkinje cells are the sole output neurons from the cerebellar cortex and therefore play crucial roles in the overall function of the cerebellum. The type-1 metabotropic glutamate receptor (mGluR1) is a key “hub” molecule that is critically involved in the regulation of synaptic wiring, excitability, synaptic response, and synaptic plasticity of Purkinje cells. In this review, we aim to highlight how mGluR1 controls these events in Purkinje cells. We also describe emerging evidence that altered mGluR1 signaling in Purkinje cells underlies cerebellar dysfunctions in several clinically relevant mouse models of human ataxias.
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Affiliation(s)
- Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takaki Watanabe
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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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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Synapse-Specific Reinnervation in the Injured Brain. J Neurosci 2016; 36:10239-10241. [PMID: 27707961 DOI: 10.1523/jneurosci.2041-16.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/23/2016] [Indexed: 11/21/2022] Open
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Piochon C, Kano M, Hansel C. LTD-like molecular pathways in developmental synaptic pruning. Nat Neurosci 2016; 19:1299-310. [PMID: 27669991 PMCID: PMC5070480 DOI: 10.1038/nn.4389] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 07/27/2016] [Indexed: 02/06/2023]
Abstract
In long-term depression (LTD) at synapses in the adult brain, synaptic strength is reduced in an experience-dependent manner. LTD thus provides a cellular mechanism for information storage in some forms of learning. A similar activity-dependent reduction in synaptic strength also occurs in the developing brain and there provides an essential step in synaptic pruning and the postnatal development of neural circuits. Here we review evidence suggesting that LTD and synaptic pruning share components of their underlying molecular machinery and may thus represent two developmental stages of the same type of synaptic modulation that serve different, but related, functions in neural circuit plasticity. We also assess the relationship between LTD and synaptic pruning in the context of recent findings of LTD dysregulation in several mouse models of autism spectrum disorder (ASD) and discuss whether LTD deficits can indicate impaired pruning processes that are required for proper brain development.
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Affiliation(s)
- Claire Piochon
- Department of Neurobiology, University of Chicago, Chicago, Illinois, USA
- Department of Physiology, Northwestern University, Chicago, Illinois, USA
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Christian Hansel
- Department of Neurobiology, University of Chicago, Chicago, Illinois, USA
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The Metabotropic Glutamate Receptor Subtype 1 Mediates Experience-Dependent Maintenance of Mature Synaptic Connectivity in the Visual Thalamus. Neuron 2016; 91:1097-1109. [PMID: 27545713 DOI: 10.1016/j.neuron.2016.07.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 04/18/2016] [Accepted: 07/19/2016] [Indexed: 11/23/2022]
Abstract
Neural circuits formed during postnatal development have to be maintained stably thereafter, but their mechanisms remain largely unknown. Here we report that the metabotropic glutamate receptor subtype 1 (mGluR1) is essential for the maintenance of mature synaptic connectivity in the dorsal lateral geniculate nucleus (dLGN). In mGluR1 knockout (mGluR1-KO) mice, strengthening and elimination at retinogeniculate synapses occurred normally until around postnatal day 20 (P20). However, during the subsequent visual-experience-dependent maintenance phase, weak retinogeniculate synapses were newly recruited. These changes were similar to those of wild-type (WT) mice that underwent visual deprivation or inactivation of mGluR1 in the dLGN from P21. Importantly, visual deprivation was ineffective in mGluR1-KO mice, and the changes induced by visual deprivation in WT mice were rescued by pharmacological activation of mGluR1 in the dLGN. These results demonstrate that mGluR1 is crucial for the visual-experience-dependent maintenance of mature synaptic connectivity in the dLGN.
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