Functional architecture and structural dynamics at the presynaptic Active Zone

突触前通过Ca 2+介导的突触囊泡（SV）融合将动作电位转换为神经递质释放，以毫秒的速度和数百赫兹的持续速率，需要有效的Ca 2+分泌偶联、快速补充和SV物质的有效清除。活动区（AZ）是一种富含蛋白质的突触前结构，组织SV的释放、补充和再循环，并使突触前和突触后对齐。我们的尖端技术，称为“闪光和冻结”，克服了以前的时间分辨率的限制，现在允许我们构建基于电子和超分辨率光学显微镜分析的前所未有的时空分辨率的突触前结构动态的延时电影。用这种方法研究突触前将使我们能够解决1）AZ模块如何定义SV融合位点和跨突触组织; 2）确定SV蛋白的融合后动力学和再循环;以及3）检查超快融合后SV补充到AZ的性质和机制。通过将融合后AZ和SV之间的分子，功能和结构动力学联系起来，我们将获得对突触前功能的前所未有的机械见解，这是通过设计原则最终重建突触功能的关键一步。

Presynapses transduce action potentials into neurotransmitter release by means of Ca2+ mediated synaptic vesicle (SV) fusion, at millisecond speed and at sustained rates of hundreds of hertz, demanding efficient Ca2+ secretion coupling, rapid replenishment and efficient clearance of SV material. The active zone (AZ), a protein-rich presynaptic structure, organizes release, replenishment and recycling of SVs, and aligns the pre- with the postsynapse. Our cutting-edge technology, termed “flash-and-freeze”, overcomes previous limits in temporal resolution and allows us now to construct time-lapse movies of presynaptic structural dynamics at unprecedented spatiotemporal resolution based on electron and super resolution light microscopy analyses. Studying the presynapse with such methods will allow us to address 1) how AZ modules define SV fusion sites and trans-synaptic organization; 2) determine the post-fusion dynamics and recycling of SV proteins; and 3) examine the nature and mechanism of ultrafast post-fusion SV replenishment to the AZ. By linking molecular, functional and structural dynamics between AZ and SVs following fusion, we will gain unprecedented mechanistic insights into presynapse function, a crucial step in ultimately reconstituting synaptic function by design principles.