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Wiegert JS, Pulin M, Gee CE, Oertner TG. The fate of hippocampal synapses depends on the sequence of plasticity-inducing events. eLife 2018; 7:39151. [PMID: 30311904 PMCID: PMC6205809 DOI: 10.7554/elife.39151] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/11/2018] [Indexed: 01/31/2023] Open
Abstract
Synapses change their strength in response to specific activity patterns. This functional plasticity is assumed to be the brain’s primary mechanism for information storage. We used optogenetic stimulation of rat hippocampal slice cultures to induce long-term potentiation (LTP), long-term depression (LTD), or both forms of plasticity in sequence. Two-photon imaging of spine calcium signals allowed us to identify stimulated synapses and to follow their fate for the next 7 days. We found that plasticity-inducing protocols affected the synapse’s chance for survival: LTP increased synaptic stability, LTD destabilized synapses, and the effect of the last stimulation protocol was dominant over earlier stimulations. Interestingly, most potentiated synapses were resistant to depression-inducing protocols delivered 24 hr later. Our findings suggest that activity-dependent changes in the transmission strength of individual synapses are transient, but have long-lasting consequences for synaptic lifetime.
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Affiliation(s)
- J Simon Wiegert
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mauro Pulin
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christine Elizabeth Gee
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas G Oertner
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Nakahata Y, Yasuda R. Plasticity of Spine Structure: Local Signaling, Translation and Cytoskeletal Reorganization. Front Synaptic Neurosci 2018; 10:29. [PMID: 30210329 PMCID: PMC6123351 DOI: 10.3389/fnsyn.2018.00029] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/07/2018] [Indexed: 12/31/2022] Open
Abstract
Dendritic spines are small protrusive structures on dendritic surfaces, and function as postsynaptic compartments for excitatory synapses. Plasticity of spine structure is associated with many forms of long-term neuronal plasticity, learning and memory. Inside these small dendritic compartments, biochemical states and protein-protein interactions are dynamically modulated by synaptic activity, leading to the regulation of protein synthesis and reorganization of cytoskeletal architecture. This in turn causes plasticity of structure and function of the spine. Technical advances in monitoring molecular behaviors in single dendritic spines have revealed that each signaling pathway is differently regulated across multiple spatiotemporal domains. The spatial pattern of signaling activity expands from a single spine to the nearby dendritic area, dendritic branch and the nucleus, regulating different cellular events at each spatial scale. Temporally, biochemical events are typically triggered by short Ca2+ pulses (~10–100 ms). However, these signals can then trigger activation of downstream protein cascades that can last from milliseconds to hours. Recent imaging studies provide many insights into the biochemical processes governing signaling events of molecular assemblies at different spatial localizations. Here, we highlight recent findings of signaling dynamics during synaptic plasticity and discuss their roles in long-term structural plasticity of dendritic spines.
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Affiliation(s)
- Yoshihisa Nakahata
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience (MPFI), Jupiter, FL, United States
| | - Ryohei Yasuda
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience (MPFI), Jupiter, FL, United States
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De Franceschi N, Alqabandi M, Miguet N, Caillat C, Mangenot S, Weissenhorn W, Bassereau P. The ESCRT protein CHMP2B acts as a diffusion barrier on reconstituted membrane necks. J Cell Sci 2018; 132:jcs.217968. [PMID: 29967034 DOI: 10.1242/jcs.217968] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/25/2018] [Indexed: 01/23/2023] Open
Abstract
Endosomal sorting complexes required for transport (ESCRT)-III family proteins catalyze membrane remodeling processes that stabilize and constrict membrane structures. It has been proposed that stable ESCRT-III complexes containing CHMP2B could establish diffusion barriers at the post-synaptic spine neck. In order to better understand this process, we developed a novel method based on fusion of giant unilamellar vesicles to reconstitute ESCRT-III proteins inside GUVs, from which membrane nanotubes are pulled. The new assay ensures that ESCRT-III proteins polymerize only when they become exposed to physiologically relevant membrane topology mimicking the complex geometry of post-synaptic spines. We establish that CHMP2B, both full-length and with a C-terminal deletion (ΔC), preferentially binds to membranes containing phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. Moreover, we show that CHMP2B preferentially accumulates at the neck of membrane nanotubes, and provide evidence that CHMP2B-ΔC prevents the diffusion of PI(4,5)P2 lipids and membrane-bound proteins across the tube neck. This indicates that CHMP2B polymers formed at a membrane neck may function as a diffusion barrier, highlighting a potential important function of CHMP2B in maintaining synaptic spine structures.
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Affiliation(s)
- Nicola De Franceschi
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005, Paris, France
| | - Maryam Alqabandi
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005, Paris, France
| | - Nolwenn Miguet
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71, avenue des Martyrs, 38000 Grenoble, France
| | - Christophe Caillat
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71, avenue des Martyrs, 38000 Grenoble, France
| | - Stephanie Mangenot
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005, Paris, France
| | - Winfried Weissenhorn
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71, avenue des Martyrs, 38000 Grenoble, France
| | - Patricia Bassereau
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France .,Sorbonne Université, 75005, Paris, France
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Baluška F, Mancuso S. Plant Cognition and Behavior: From Environmental Awareness to Synaptic Circuits Navigating Root Apices. MEMORY AND LEARNING IN PLANTS 2018. [DOI: 10.1007/978-3-319-75596-0_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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55
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Biophysics of the Brain: From Molecules to Networks. Biophys J 2017; 113:E1. [PMID: 29079011 DOI: 10.1016/j.bpj.2017.10.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 10/18/2017] [Indexed: 11/22/2022] Open
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