Selective activation of Ca2+-activated K+ channels by co-localized Ca2+ channels in hippocampal neurons

Neil V. Marrion, Steven Tavalin

Research output: Contribution to journalArticle

417 Citations (Scopus)

Abstract

Calcium entry through voltage-gated calcium channels can activate either large- (BK) or small- (SK) conductance calcium-activated potassium channels. In hippocampal neurons, activation of BK channels underlies the falling phase of an action potential and generation of the fast afterhyperpolarization (AHP). In contrast, SK channel activation underlies generation of the slow AHP after a burst of action potentials. The source of calcium for BK channel activation is unknown, but the slow AHP is blocked by dihydropyridine antagonists, indicating that L-type calcium channels provide the calcium for activation of SK channels. It is not understood how this specialized coupling between calcium and potassium channels is achieved. Here we study channel activity in cell-attached patches from hippocampal neurons and report a unique specificity of coupling. L-type channels activate SK channels only, without activating BK channels present in the same patch. The delay between the opening of L-type channels and SK channels indicates that these channels are 50-150 nm apart. In contrast, N-type calcium channels activate BK channels only, with opening of the two channel types being nearly coincident. This temporal association indicates that N and BK channels are very close. Finally, P/Q-type calcium channels do not couple to either SK or BK channels. These data indicate an absolute segregation of coupling-between channels, and illustrate the functional importance of submembrane calcium microdomains.

Original languageEnglish (US)
Pages (from-to)900-905
Number of pages6
JournalNature
Volume395
Issue number6705
DOIs
StatePublished - Oct 29 1998

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Large-Conductance Calcium-Activated Potassium Channels
Calcium-Activated Potassium Channels
Neurons
Calcium Channels
Calcium
Action Potentials
Small-Conductance Calcium-Activated Potassium Channels
Q-Type Calcium Channels
P-Type Calcium Channels
N-Type Calcium Channels
L-Type Calcium Channels
Potassium Channels

All Science Journal Classification (ASJC) codes

  • General

Cite this

Selective activation of Ca2+-activated K+ channels by co-localized Ca2+ channels in hippocampal neurons. / Marrion, Neil V.; Tavalin, Steven.

In: Nature, Vol. 395, No. 6705, 29.10.1998, p. 900-905.

Research output: Contribution to journalArticle

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