T-type calcium channels consolidate tonic action potential output of thalamic neurons to neocortex.
J Neurosci
; 32(35): 12228-36, 2012 Aug 29.
Article
en En
| MEDLINE
| ID: mdl-22933804
The thalamic output during different behavioral states is strictly controlled by the firing modes of thalamocortical neurons. During sleep, their hyperpolarized membrane potential allows activation of the T-type calcium channels, promoting rhythmic high-frequency burst firing that reduces sensory information transfer. In contrast, in the waking state thalamic neurons mostly exhibit action potentials at low frequency (i.e., tonic firing), enabling the reliable transfer of incoming sensory inputs to cortex. Because of their nearly complete inactivation at the depolarized potentials that are experienced during the wake state, T-channels are not believed to modulate tonic action potential discharges. Here, we demonstrate using mice brain slices that activation of T-channels in thalamocortical neurons maintained in the depolarized/wake-like state is critical for the reliable expression of tonic firing, securing their excitability over changes in membrane potential that occur in the depolarized state. Our results establish a novel mechanism for the integration of sensory information by thalamocortical neurons and point to an unexpected role for T-channels in the early stage of information processing.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Tálamo
/
Potenciales de Acción
/
Neocórtex
/
Canales de Calcio Tipo T
/
Neuronas
Límite:
Animals
Idioma:
En
Revista:
J Neurosci
Año:
2012
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos