Calcium cooperativity of exocytosis as a measure of Ca 2+ channel domain overlap

Document Type

Article

Publication Date

6-29-2011

Abstract

The number of Ca 2+ channels contributing to the exocytosis of a single neurotransmitter vesicle in a presynaptic terminal has been a question of significant interest and debate, and is important for a full understanding of localized Ca 2+ signaling in general, and synaptic physiology in particular. This is usually estimated by measuring the sensitivity of the neurotransmitter release rate to changes in the synaptic Ca 2+ current, which is varied using appropriate voltage-clamp protocols or via pharmacological Ca 2+ channel block under the condition of constant single-channel Ca 2+ current. The slope of the resulting log-log plot of transmitter release rate versus presynaptic Ca 2+ current is termed Ca 2+ current cooperativity of exocytosis, and provides indirect information about the underlying presynaptic morphology. In this review, we discuss the relationship between the Ca 2+ current cooperativity and the average number of Ca 2+ channels participating in the exocytosis of a single vesicle, termed the Ca 2+channel cooperativity. We relate these quantities to the morphology of the presynaptic active zone. We also review experimental studies of Ca 2+ current cooperativity and its modulation during development in different classes of synapses.

Identifier

79958851367 (Scopus)

Publication Title

Brain Research

External Full Text Location

https://doi.org/10.1016/j.brainres.2011.05.011

e-ISSN

00068993

ISSN

00068993

PubMed ID

21621748

First Page

126

Last Page

138

Volume

1398

Grant

DMS-0817703

Fund Ref

National Science Foundation

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