Ca(v)1.3 and BK channels for timing and regulating cell firing.
Mol Neurobiol
; 42(3): 185-98, 2010 Dec.
Article
en En
| MEDLINE
| ID: mdl-21088933
ABSTRACT
L-type Ca(2+) channels (LTCCs, Ca(v)1) open readily during membrane depolarization and allow Ca(2+) to enter the cell. In this way, LTCCs regulate cell excitability and trigger a variety of Ca(2+)-dependent physiological processes such as excitation-contraction coupling in muscle cells, gene expression, synaptic plasticity, neuronal differentiation, hormone secretion, and pacemaker activity in heart, neurons, and endocrine cells. Among the two major isoforms of LTCCs expressed in excitable tissues (Ca(v)1.2 and Ca(v)1.3), Ca(v)1.3 appears suitable for supporting a pacemaker current in spontaneously firing cells. It has steep voltage dependence and low threshold of activation and inactivates slowly. Using Ca(v)1.3(-/-) KO mice and membrane current recording techniques such as the dynamic and the action potential clamp, it has been possible to resolve the time course of Ca(v)1.3 pacemaker currents that regulate the spontaneous firing of dopaminergic neurons and adrenal chromaffin cells. In several cell types, Ca(v)1.3 is selectively coupled to BK channels within membrane nanodomains and controls both the firing frequency and the action potential repolarization phase. Here we review the most critical aspects of Ca(v)1.3 channel gating and its coupling to large conductance BK channels recently discovered in spontaneously firing neurons and neuroendocrine cells with the aim of furnishing a converging view of the role that these two channel types play in the regulation of cell excitability.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Potenciales de Acción
/
Activación del Canal Iónico
/
Canales de Calcio Tipo L
/
Canales de Potasio de Gran Conductancia Activados por el Calcio
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Neurobiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEUROLOGIA
Año:
2010
Tipo del documento:
Article
País de afiliación:
Italia