Influence of synaptic vesicle position on release probability and exocytotic fusion mode

Science. 2012 Mar 16;335(6074):1362-6. doi: 10.1126/science.1216937. Epub 2012 Feb 16.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Exocytosis*
  • Imaging, Three-Dimensional
  • Membrane Fusion*
  • Microscopy, Fluorescence
  • Neurons / physiology
  • Neurons / ultrastructure
  • Presynaptic Terminals / physiology*
  • Presynaptic Terminals / ultrastructure
  • Rats
  • Synaptic Transmission
  • Synaptic Vesicles / physiology*
  • Synaptic Vesicles / ultrastructure
  • Trypan Blue

Substances

  • Trypan Blue