Probing the segregation of evoked and spontaneous neurotransmission via photobleaching and recovery of a fluorescent glutamate sensor.
Probing the segregation of evoked and spontaneous neurotransmission via photobleaching and recovery of a fluorescent glutamate sensor.
复制标题
通过光漂白和恢复荧光谷氨酸传感器的诱发和自发神经传递的分离。
DOI：
10.7554/elife.76008
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发表时间：
2022-04-14
期刊：
影响因子：
7.7
通讯作者：
Kavalali, Ege T.
中科院分区：
文献类型：
--
作者：
Wang, Camille S.;Chanaday, Natali L.;Monteggia, Lisa M.;Kavalali, Ege T.
关键词：
突触维持动作电位诱发的和自发的神经递质释放;然而，在单个突触内这两种形式的释放的组织仍然不清楚。在这里，我们使用的iGluSnFR，荧光探针，检测谷氨酸的光漂白性能，调查诱发和自发释放在原代海马文化的突触下组织。在非神经元细胞和神经元树突中，iGluSnFR荧光被强烈光漂白，并通过非光漂白探针的扩散恢复，时间常数约为10 s。光漂白后，虽然诱发的iGluSnFR事件可以迅速抑制，他们的恢复需要几个小时。与此相反，iGluSnFR的自发释放的反应是比较有弹性的光漂白，除非整个池的iGluSnFR被激活谷氨酸灌注。光漂白对不同模式的神经传递的这种差异效应与突触下组织一致，其中诱发的谷氨酸释放的位点是聚集的，并且相应的iGluSnFR探针是扩散限制的，而自发释放位点广泛分布在具有容易扩散的iGluSnFR探针的突触上。
Synapses maintain both action potential-evoked and spontaneous neurotransmitter release; however, organization of these two forms of release within an individual synapse remains unclear. Here, we used photobleaching properties of iGluSnFR, a fluorescent probe that detects glutamate, to investigate the subsynaptic organization of evoked and spontaneous release in primary hippocampal cultures. In nonneuronal cells and neuronal dendrites, iGluSnFR fluorescence is intensely photobleached and recovers via diffusion of nonphotobleached probes with a time constant of ~10 s. After photobleaching, while evoked iGluSnFR events could be rapidly suppressed, their recovery required several hours. In contrast, iGluSnFR responses to spontaneous release were comparatively resilient to photobleaching, unless the complete pool of iGluSnFR was activated by glutamate perfusion. This differential effect of photobleaching on different modes of neurotransmission is consistent with a subsynaptic organization where sites of evoked glutamate release are clustered and corresponding iGluSnFR probes are diffusion restricted, while spontaneous release sites are broadly spread across a synapse with readily diffusible iGluSnFR probes.