Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
Science. 2012 Mar 16;335(6074):1362-6. doi: 10.1126/science.1216937. Epub 2012 Feb 16.
Neurotransmission depends on movements of transmitter-laden synaptic vesicles, but accurate, nanometer-scale monitoring of vesicle dynamics in presynaptic terminals has remained elusive. Here, we report three-dimensional, real-time tracking of quantum dot-loaded single synaptic vesicles with an accuracy of 20 to 30 nanometers, less than a vesicle diameter. Determination of the time, position, and mode of fusion, aided by trypan blue quenching of Qdot fluorescence, revealed that vesicles starting close to their ultimate fusion sites tended to fuse earlier than those positioned farther away. The mode of fusion depended on the prior motion of vesicles, with long-dwelling vesicles preferring kiss-and-run rather than full-collapse fusion. Kiss-and-run fusion events were concentrated near the center of the synapse, whereas full-collapse fusion events were broadly spread.
神经传递依赖于携带递质的突触小泡的运动，但在突触前末梢中对小泡动力学进行准确的、纳米级别的监测一直难以实现。在这里，我们报告了对量子点负载的单个突触小泡进行三维、实时跟踪的方法，其精度达到 20 到 30 纳米，小于小泡直径。通过锥虫蓝猝灭 Qdot 荧光来辅助确定融合的时间、位置和模式，结果表明，靠近最终融合位点开始的小泡比那些位于更远位置的小泡融合得更早。融合的模式取决于小泡的先前运动，停留时间较长的小泡更倾向于 kiss-and-run 融合，而不是完全塌陷融合。kiss-and-run 融合事件集中在突触的中心附近，而完全塌陷融合事件则广泛分布。
