Releasable pools and the kinetics of exocytosis in adrenal chromaffin cells

Frank T. Horrigan, Richard J. Bookman

Research output: Contribution to journalArticle

204 Citations (Scopus)

Abstract

Using high resolution capacitance (C(m)) measurement techniques, we mapped the kinetics of exocytosis evoked by brief (5-100 ms) depolarizations that activate voltage-dependent Ca2+ channels in rat adrenal chromaffin cells. After correcting the C(m) signal for contributions from Na+ channel-gating charge movements, the initial kinetics of exocytosis were consistent with depolarization-triggered release occurring initially from an immediately releasable pool of only ~ 17 secretory vesicles. In contrast, repetitive application of longer depolarizations evoked release from a distinct, larger readily releasable pool of ~170 vesicles. Our results suggest that the secretory response of a chromaffin cell to an action potential is limited by the size of the immediately releasable pool rather than by a fusion mechanism that is slower than that at synapses.

Original languageEnglish
Pages (from-to)1119-1129
Number of pages11
JournalNeuron
Volume13
Issue number5
DOIs
StatePublished - Dec 13 1994
Externally publishedYes

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Chromaffin Cells
Exocytosis
Secretory Vesicles
Synapses
Action Potentials

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Releasable pools and the kinetics of exocytosis in adrenal chromaffin cells. / Horrigan, Frank T.; Bookman, Richard J.

In: Neuron, Vol. 13, No. 5, 13.12.1994, p. 1119-1129.

Research output: Contribution to journalArticle

Horrigan, Frank T. ; Bookman, Richard J. / Releasable pools and the kinetics of exocytosis in adrenal chromaffin cells. In: Neuron. 1994 ; Vol. 13, No. 5. pp. 1119-1129.
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