Release probability is regulated by the size of the readily releasable vesicle pool at excitatory synapses in hippocampus
Release probability is regulated by the size of the readily releasable vesicle pool at excitatory synapses in hippocampus
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DOI：
10.1016/s0736-5748(02)00015-1
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发表时间：
2002-06-01
影响因子：
1.8
通讯作者：
Dobrunz, LE
中科院分区：
文献类型：
--
作者：
Dobrunz, LE
中枢神经系统中的突触可能非常不可靠：动作电位对单个突触的刺激通常不会导致神经递质的释放。然而，递质释放的概率并不总是相同的，这使得突触传递的平均强度可以通过调节释放概率来调节。释放概率被认为是由融合能力囊泡（易释放囊泡池）的数量和每个囊泡的释放概率决定的。来自单个突触的研究表明，在海马切片和培养细胞中，释放概率与兴奋性CA3-CA1突触群中容易释放的囊泡池的大小相关。在这里，我提供的证据表明，释放概率与单个突触内易释放囊泡池的大小之间存在相同的关系，进一步表明易释放池的大小有助于决定释放概率。此外，使用一个简单的模型，我检查了容易释放的囊泡的数量和每个囊泡的平均释放概率在高频刺激序列中是如何变化的，并提供了囊泡之间释放概率不均匀性的证据。(c) 2002 isdn。Elsevier Science Ltd.出版。版权所有。
Synapses in the central nervous system can be very unreliable: stimulation of an individual synapse by an action potential often does not lead to release of neurotransmitter. The probability of transmitter release is not always the same, however, which enables the average strength of synaptic transmission to be regulated by modulation of release probability. Release probability is believed to be determined by the number of fusion competent vesicles (the readily releasable vesicle pool) and the release probability per vesicle. Studies from single synapses have shown that release probability correlates with the size of the readily releasable pool of vesicles across the population of excitatory CA3-CA1 synapses, both in hippocampal slices and in cultured cells. Here I present evidence that the same relationship exists between release probability and the size of the readily releasable vesicle pool within individual synapses, further suggesting that the size of the readily releasable pool helps determine release probability. In addition, using a simple model, I examine how both the number of readily releasable vesicles and the average release probability per vesicle change during trains of high frequency stimulation, and present evidence for non-uniformity of the release probability among vesicles. (C) 2002 ISDN. Published by Elsevier Science Ltd. All rights reserved.