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Parvalbumin/GABA cells in the monkey cerebral cortex: gap junctions, chandelier- and basket-terminals
| Content Provider | Semantic Scholar |
|---|---|
| Author | Yamashita, Akiko Oishi, Takao Katsuyama, Narumi Taira, Masato Hayashi, Motoharu |
| Copyright Year | 2009 |
| Abstract | s S143 However, the temporal and spatial distribution patterns of extrasynaptic glutamate have remained elusive. Here we directly imaged and quantified the extrasynaptic glutamate dynamics using a fluorescent indicator of glutamate (EOS, glutamate (E) optical sensor). We found that physiologically relevant patterns of synaptic inputs induce the micromolar level of extrasynaptic glutamate pooling in acute brain slices. This demonstrates that physiological synaptic activities generate significant extrasynaptic glutamate dynamics that are sufficient for activating extrasynaptic glutamate receptors. doi:10.1016/j.neures.2009.09.713 P2-b13 Input-specific remodeling of postsynaptic density (PSD) proteins in Purkinje cell spines Toshimitsu Fuse, Haruhiko Bito Department Neurochem, University Tokyo Grad. Sch. Med., Tokyo, Japan Mature Purkinje cells receive segregated excitatory inputs from one single climbing fiber (CF) and numerous parallel fibers (PFs). Although the composition of synaptic proteins differs depending on the incoming fibers, the molecular mechanisms underlying such input-specific specification remain poorly understood. We found that Shank1A/Synamon is abundant at the PSD of PF synapses but is hardly detected at CF synapses in the mature cerebellum. To identify a potentially causal link between CF activity and reduced Shank1A, we applied stimuli that mimic CF activity, either by opening P/Q-type Ca2+ channels (55 mM KCl) or AMPA receptors (0.5 M AMPA), and measured synaptic Shank1A, in mature cultured Purkinje neurons that lack CF-like inputs. Indeed, Shank1A clusters decreased robustly, and this was abolished in the presence of MG132, suggesting that Shank1A is actively degraded by the ubiquitin proteasome system. Interestingly, treatment with either -CTX MVIIC or -agaIVA suppressed this degradation, consistent with the role of sustained Ca2+-influx via P/Q-type Ca2+ channels in limiting Shank1A content. doi:10.1016/j.neures.2009.09.714 P2-b14 Dynamics of synaptic vesicle exocytosis at the level of single synapses revealed by optical glutamate imaging Hirokazu Sakamoto, Shigeyuki Namiki, Sho Iinuma, Kenzo Hirose Department Neurobiol, University of Tokyo, Tokyo, Japan Exocytosis of synaptic vesicles normally occurs at presynaptic release site. However, the number of release sites (Nsite) and the number of releasable vesicles (Nves) at a central synapse, which typically contains only one active zone, have not been revealed. In this study, we applied optical glutamate imaging to directly measure glutamate released from single hippocampal synapses. Fluctuation analysis based on a binomial model and deconvolution analysis enables us to estimate Nsite and Nves, respectively. Interestingly, although Nsite and Nves strongly correlated, Nves is usually larger than Nsite. This result indicates that limited vesicles in releasable pool are released by a single presynaptic action potential. Furthermore, the release rate per vesicle was fast at synapses which had relatively large Nsite. Therefore, Nsite is a key determinant of dynamics of synaptic vesicle exocytosis, and contributes to short term synaptic plasticity at the level of single synapses. doi:10.1016/j.neures.2009.09.715 P2-b15 The role of the N-terminal domain of glutamate receptor 2 in synapse formation Takeshi Uemura, Masayoshi Mishina Department of Mol. Neurobiol. & Pharmacol., University of Tokyo, Tokyo, |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.neures.2009.09.719 |
| Volume Number | 65 |
| Alternate Webpage(s) | https://api.elsevier.com/content/article/pii/S0168010209009894 |
| Alternate Webpage(s) | https://www.sciencedirect.com/science/article/pii/S0168010209009894?dgcid=api_sd_search-api-endpoint |
| Journal | Neuroscience Research |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
