美国约翰霍普金斯大学医学院Shigeki Watanabe研究组取得最新进展。他们发现突触小泡暂时停靠以补充释放部位。该项研究成果发表在2020年9月28日的《自然-神经科学》杂志上。
为了捕获在培养的小鼠海马突触中的突触小泡胞吐作用，他们通过电场刺激诱导单动电位，然后使神经元经受高压冷冻以通过电镜检查其形态。在同步释放期间，多个囊泡可在单个活性区融合。同步释放期间的融合分布在整个活动区域中，而异步释放期间的融合则偏向活动区域的中心。刺激后，所有突触中停靠的囊泡总数减少约40％。在14毫秒内，新的囊泡会被吸收并完全补充停靠池，但是这种停靠是短暂的，它们会在100毫秒内撤离或融合。
这些结果表明，突触小泡募集到释放部位是快速且可逆的。
据了解，突触小泡在动作电位后与质膜融合以释放神经递质，之后新的囊泡必须“停靠”以补充空出的释放部位。
附：英文原文
Title: Synaptic vesicles transiently dock to refill release sites
Author: Grant F. Kusick, Morven Chin, Sumana Raychaudhuri, Kristina Lippmann, Kadidia P. Adula, Edward J. Hujber, Thien Vu, M. Wayne Davis, Erik M. Jorgensen, Shigeki Watanabe
Issue&Volume: 2020-09-28
Abstract: Synaptic vesicles fuse with the plasma membrane to release neurotransmitter following an action potential, after which new vesicles must ‘dock’ to refill vacated release sites. To capture synaptic vesicle exocytosis at cultured mouse hippocampal synapses, we induced single action potentials by electrical field stimulation, then subjected neurons to high-pressure freezing to examine their morphology by electron microscopy. During synchronous release, multiple vesicles can fuse at a single active zone. Fusions during synchronous release are distributed throughout the active zone, whereas fusions during asynchronous release are biased toward the center of the active zone. After stimulation, the total number of docked vesicles across all synapses decreases by ~40%. Within 14ms, new vesicles are recruited and fully replenish the docked pool, but this docking is transient and they either undock or fuse within 100ms. These results demonstrate that the recruitment of synaptic vesicles to release sites is rapid and reversible.
DOI: 10.1038/s41593-020-00716-1
Source: https://www.nature.com/articles/s41593-020-00716-1
Nature Neuroscience：《自然—神经科学》，创刊于1998年。隶属于施普林格·自然出版集团，最新IF：28.771
官方网址：https://www.nature.com/neuro/
投稿链接：https://mts-nn.nature.com/cgi-bin/main.plex
本期文章：《自然—神经科学》：Online/在线发表
