Influence of Synaptic Vesicle Position on Release Probability and Exocytotic Fusion Mode

• Published in: Science (American Association for the Advancement of Science) Vol. 335; no. 6074; pp. 1362 - 1366
• Main Authors: Park, Hyokeun, Li, Yulong, Tsien, Richard W.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 16.03.2012; The American Association for the Advancement of Science
• Subjects: Animals; Biological and medical sciences; Cell physiology; Cells, Cultured; Centroids; Exocytosis; Fluorescence; Fundamental and applied biological sciences. Psychology; Fusion; Imaging; Imaging, Three-Dimensional; Membrane Fusion; Microscopy, Fluorescence; Molecular and cellular biology; Neurons; Neurons - physiology; Neurons - ultrastructure; Neuroscience; Neurotransmission; Neurotransmitters; Presynaptic Terminals - physiology; Presynaptic Terminals - ultrastructure; Quantum theory; Rats; Receptors; Recycling; Synapses; Synaptic Transmission; Synaptic Vesicles - physiology; Synaptic Vesicles - ultrastructure; Trajectories; Trypan Blue; Synaptic vesicle; Exocytosis; Position; Neurotransmission
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1216937

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.