Mean Synaptic Vesicle Size Varies Among Individual Excitatory Hippocampal Synapses
Mean Synaptic Vesicle Size Varies Among Individual Excitatory Hippocampal Synapses
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DOI：
10.1002/syn.20567
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发表时间：
2008-12-01
期刊：
影响因子：
2.3
通讯作者：
Schikorski, Thomas
中科院分区：
文献类型：
--
作者：
Hu, Yunming;Qu, Lei;Schikorski, Thomas
在Katz的量子理论中，量子被定义为释放一小包但统一的神经递质(Katz，1969)。随着De Robertis和Bennett，1955在第一张电子显微照片中发现突触小泡(SV)，人们立即假设SVS内包装着神经递质，大小均匀的SVS是量子的结构关联。今天，这一假说被广泛接受，并构成了我们理解突触功能的基础。突触后机制，如调节突触后受体的数量和电导，是量子幅度的决定因素(Malenka，2003)。突触前机制也可能有助于量子幅度的调节，最近，调节小泡中神经递质数量的机制受到了相当大的关注(Edwards，2007)。SV的大小是神经递质数量的决定因素之一。基于电子显微镜研究，目前认为SV直径在30到80 nm之间(Fox，1988；Harris和Sultan，1995；Schikorski和Stevens，1997)。人们还普遍认为，对于特定的突触类型，SV的大小是恒定的。在这里，我们探索了SV大小是否受到调节，并发现由N-甲基-D-天冬氨酸(NMDA)受体信号控制的兴奋性海马突触之间存在意想不到的差异。
In Katz’s quantal theory, a quantum is defined as the release of a small but uniform package of neurotransmitter (Katz, 1969). With the discovery of synaptic vesicles (SV) in the first electron micrographs (de Robertis and Bennett, 1955), it was immediately hypothesized that neurotransmitter is packaged inside SVs and that the uniformly sized SVs are the structural correlate of the quantum. Today, this hypothesis is widely accepted and forms the basis for our understanding of synaptic function. Postsynaptic mechanisms such as the regulation of the number and conductance of postsynaptic receptors are wellcharacterized determinants of quantal amplitude (Malenka, 2003). Presynaptic mechanisms may also contribute to the regulation of quantal amplitude and, recently, mechanisms that regulate the amount of neurotransmitter in vesicles have received considerable attention (Edwards, 2007). SV size is one determinant of the amount of neurotransmitter. Based on electron microscopic studies, it is currently believed that SV diameters range between 30 and 80 nm (Fox, 1988; Harris and Sultan, 1995; Schikorski and Stevens, 1997). It is also widely believed that SV size is constant for a particular synapse type. Here we explored if SV size is regulated and found an unanticipated variability among excitatory hippocampal synapses controlled by N-methyl-D-aspartic acid (NMDA) receptor signaling.