Department of Anesthesiology

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A heterogeneous "resting" pool of synaptic vesicles that is dynamically interchanged across boutons in mammalian CNS synapses.

TitleA heterogeneous "resting" pool of synaptic vesicles that is dynamically interchanged across boutons in mammalian CNS synapses.
Publication TypeJournal Article
Year of Publication2008
AuthorsFernandez-Alfonso T, Ryan TA
JournalBrain Cell Biol
Volume36
Issue1-4
Pagination87-100
Date Published2008 Aug
ISSN1559-7113
KeywordsAction Potentials, Animals, Animals, Newborn, Cells, Cultured, Electric Stimulation, Electrophysiology, Green Fluorescent Proteins, Hippocampus, Membrane Fusion, Microscopy, Confocal, Microscopy, Fluorescence, Neurons, Presynaptic Terminals, Rats, Rats, Sprague-Dawley, Synapses, Synaptic Transmission, Synaptic Vesicles, Synaptotagmin I, Vesicle-Associated Membrane Protein 2, Vesicular Glutamate Transport Protein 1
Abstract

Using pHluorin-tagged synaptic vesicle proteins we have examined the partitioning of these probes into recycling and nonrecycling pools at hippocampal nerve terminals in cell culture. Our studies show that for three of the major synaptic vesicle components, vGlut-1, VAMP-2, and Synaptotagmin I, approximately 50-60% of the tagged protein appears in a recycling pool that responds readily to sustained action potential stimulation by mobilizing and fusing with the plasma membrane, while the remainder is targeted to a nonrecycling, acidic compartment. The fraction of recycling and nonrecycling (or resting) pools varied significantly across boutons within an individual axon, from 100% resting (silent) to 100% recycling. Single-bouton bleaching studies show that recycling and resting pools are dynamic and exchange between synaptic boutons. The quantitative parameters that can be extracted with the approaches outlined here should help elucidate the potential functional role of the resting vesicle pool.

DOI10.1007/s11068-008-9030-y
Alternate JournalBrain Cell Biol
PubMed ID18941900
PubMed Central IDPMC2924874
Grant ListNS24992 / NS / NINDS NIH HHS / United States
R01 NS036942-12 / NS / NINDS NIH HHS / United States