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Fekete A, Nakamura Y, Yang YM, Herlitze S, Mark MD, DiGregorio DA, Wang LY. Underpinning heterogeneity in synaptic transmission by presynaptic ensembles of distinct morphological modules. Nat Commun 2019; 10:826. [PMID: 30778063 PMCID: PMC6379440 DOI: 10.1038/s41467-019-08452-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 12/28/2018] [Indexed: 11/09/2022] Open
Abstract
Synaptic heterogeneity is widely observed but its underpinnings remain elusive. We addressed this issue using mature calyx of Held synapses whose numbers of bouton-like swellings on stalks of the nerve terminals inversely correlate with release probability (Pr). We examined presynaptic Ca2+ currents and transients, topology of fluorescently tagged knock-in Ca2+ channels, and Ca2+ channel-synaptic vesicle (SV) coupling distance using Ca2+ chelator and inhibitor of septin cytomatrix in morphologically diverse synapses. We found that larger clusters of Ca2+ channels with tighter coupling distance to SVs elevate Pr in stalks, while smaller clusters with looser coupling distance lower Pr in swellings. Septin is a molecular determinant of the differences in coupling distance. Supported by numerical simulations, we propose that varying the ensemble of two morphological modules containing distinct Ca2+ channel-SV topographies diversifies Pr in the terminal, thereby establishing a morpho-functional continuum that expands the coding capacity within a single synapse population.
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Affiliation(s)
- Adam Fekete
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada
- Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Yukihiro Nakamura
- Department of Pharmacology, Jikei University School of Medicine, Nishishinbashi, Minato-ku, Tokyo, 1058461, Japan
| | - Yi-Mei Yang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada
- Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Department of Biomedical Sciences, University of Minnesota Medical School, 1035 University Drive, Duluth, MN, 55812, USA
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780, Bochum, Germany
| | - Melanie D Mark
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780, Bochum, Germany
| | - David A DiGregorio
- Unit of Dynamic Neuronal Imaging, Institut Pasteur, 25 rue du Dr Roux, 75724, Paris Cedex 15, France
- Centre National de la Recherche Scientifique (CNRS), UMR 3571, Genes, Synapses and Cognition, Institut Pasteur, 25 rue du Dr Roux, 75724, Paris Cedex 15, France
| | - Lu-Yang Wang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada.
- Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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miR-132/212 knockout mice reveal roles for these miRNAs in regulating cortical synaptic transmission and plasticity. PLoS One 2013; 8:e62509. [PMID: 23658634 PMCID: PMC3637221 DOI: 10.1371/journal.pone.0062509] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 03/25/2013] [Indexed: 01/30/2023] Open
Abstract
miR-132 and miR-212 are two closely related miRNAs encoded in the same intron of a small non-coding gene, which have been suggested to play roles in both immune and neuronal function. We describe here the generation and initial characterisation of a miR-132/212 double knockout mouse. These mice were viable and fertile with no overt adverse phenotype. Analysis of innate immune responses, including TLR-induced cytokine production and IFNβ induction in response to viral infection of primary fibroblasts did not reveal any phenotype in the knockouts. In contrast, the loss of miR-132 and miR-212, while not overtly affecting neuronal morphology, did affect synaptic function. In both hippocampal and neocortical slices miR-132/212 knockout reduced basal synaptic transmission, without affecting paired-pulse facilitation. Hippocampal long-term potentiation (LTP) induced by tetanic stimulation was not affected by miR-132/212 deletion, whilst theta burst LTP was enhanced. In contrast, neocortical theta burst-induced LTP was inhibited by loss of miR-132/212. Together these results indicate that miR-132 and/or miR-212 play a significant role in synaptic function, possibly by regulating the number of postsynaptic AMPA receptors under basal conditions and during activity-dependent synaptic plasticity.
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