Venue : Centre Broca
Shigeki Watanabe
Associate Professor
Solomon H. Snyder Department of Neuroscience,
Department of Cell Biology and the Center for Cell Dynamics,
Johns Hopkins University, Baltimore, MD 21205, USA
Invited by David Perrais (IINS)
Title
Spatial and temporal control of synaptic transmission and plasticity
Abstract
Neuronal signaling events at synapses determine circuit responses and result in specific behavioral outputs. This signaling is mediated by fusion of synaptic vesicles – the fastest membrane remodeling events in any cell, occurring within a millisecond of an action potential. Synaptic transmission is modulated on multiple times scales ranging from milliseconds to years. On the millisecond scale, even a single action potential can elicit a several-fold increase in a synapse’s response to a second stimulus, known as short-term facilitation. However, how synapses can manifest such a form of plasticity has been enigmatic. Using zap-and-freeze, which couples electrical stimulation of neurons with high-pressure freezing to visualize membrane dynamics by electron microscopy, my lab studies cellular and molecular mechanisms of synaptic transmission. In the seminar, I will discuss our recent progress on when, where, and how release sites are used and replenished.
(Kusick et al., 2020; Li et al., 2021; Vevea et al., 2021; Imoto et al., 2022)
Recent references
Imoto Y, Raychaudhuri S*, Ma Y*, Fenske P, Sandoval E, Itoh K, Blumrich E, Matsubayashi HT, Mamer L, Zarebidaki F, Söhl-Kielczynski B, Trimbuch T, Nayak S, Iwasa J, Liu J, Wu B, Ha T, Inoue T, Jorgensen EM, Cousin M, Rosenmund C, Watanabe S (2022) Dynamin is primed at endocytic sites for ultrafast endocytosis. Neuron 110:2815–2835.
Li S, Raychaudhuri S, Lee SA, Brockmann MM, Wang J, Kusick G, Prater C, Syed S, Falahati H, Ramos R, Bartol TM, Hosy E, Watanabe S (2021) Asynchronous release sites align with NMDA receptors in mouse hippocampal synapses. Nature Communications 12:677.
Vevea JD, Kusick GF, Courtney KC, Chen E, Watanabe S, Chapman ER (2021) Synaptotagmin 7 is targeted to the axonal plasma membrane through γ-secretase processing to promote synaptic vesicle docking in mouse hippocampal neurons Bellen HJ, Swartz KJ, eds. eLife 10:e67261.
Kusick GF, Chin M, Raychaudhuri S, Lippmann K, Adula KP, Hujber EJ, Vu T, Davis MW, Jorgensen EM, Watanabe S (2020) Synaptic vesicles transiently dock to refill release sites. Nat Neurosci 23:1329–1338.