神经元突触前可塑性的结构及分子基础

突触可塑性是神经元间信息传递的重要生理调控机制，它包括突触前可塑性和突触后可塑性.突触前可塑性是指通过对神经递质释放过程的干预、修饰，调节突触强度的过程.突触强度的变化，是通过影响量子的大小，活动区的个数和囊泡释放概率来实现的.而突触前囊泡活动尤为重要：从转运、搭靠、融合至内吞进入下一轮循环，每一步都是由一群互相作用的蛋白质共同完成的.

The Structural and Molecular Mechanism of Neuronal Presynaptic Plasticity

Synaptic plasticity is a physiologically important mechanism underlying neuronal information processing. In terms of expression site, synaptic plasticity can be divided into presynaptic and postsynaptic. Presynaptic plasticity is implicated in the modulation of the neurotransmitter release machinery and consequently in synaptic strength. From a physiological perspective, this type of plasticity could be derived from a change in quantal size, active zone structure, probability of transmitter release, especially, synaptic vesicle dynamics: from synaptic vesicle trafficking to the nerve terminal, docking at or fusion with the presynaptic plasma membrane, and finally, reconstitution following endocytosis. Each of these steps is mediated by the concerted activities of multiple proteins and protein complexes, thus presenting numerous points at which the cascades leading to effective neurotransmitter release could be modulated. Potential mechanisms by which the synaptic vesicle release could be modulated and synaptic activity could be silenced or enhanced at the presynaptic terminal are reviewed.