Modulation of leak K(+) channel in hypoglossal motoneurons of rats by serotonin and/or variation of pH value / 生理学报
Acta Physiologica Sinica
;
(6): 305-316, 2009.
Artigo
em Inglês
| WPRIM
| ID: wpr-302447
ABSTRACT
The cloned TWIK-related acid-sensitive K(+) channel (TASK-1) is sensitive to the pH changes within physiological pH range (pK~7.4). Recently, the native TASK-1-like channel was suggested to be the main contributor to the background (or leak) K(+) conductance in the motoneurons of the brain stem. Serotonin (5-HT) and variation of pH value in perfused solution could modulate these currents. Here we aimed to examine the properties and modulation of the currents by serotonin or variation of pH value in hypoglossal motoneurons of rats. Transverse slices were prepared from the brainstem of neonatal Sprague-Dawley rats (postnatal days 7-8). Hypoglossal motoneurons were used for the study. The leak K(+) current (TASK-1-like current) and hyperpolarization-activated cationic current (I(h)) were recorded with the whole-cell patch-clamp technique. The results showed that these currents were inhibited by acidified artificial cerebrospinal fluid (ACSF, pH 6.0) and activated by alkalized ACSF (pH 8.5). 5-HT (10 mumol/L) significantly inhibited both leak K(+) current and I(h) with depolarization of membrane potential and the occurrence of oscillation and/or spikes. Bath application of Ketanserine, an antagonist of 5-HT₂ receptor, reversed or reduced the inhibitory effect of acidified solution on leak K(+) current and I(h). The results suggest that 5-HT₂ receptors mediate the effects of acidified media on leak K(+) current and I(h) in hypoglossal motoneurons.
Texto completo:
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Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Farmacologia
/
Técnicas In Vitro
/
Tronco Encefálico
/
Serotonina
/
Ratos Sprague-Dawley
/
Transporte de Íons
/
Técnicas de Patch-Clamp
/
Biologia Celular
/
Canais de Potássio de Domínios Poros em Tandem
/
Nervo Hipoglosso
Limite:
Animais
Idioma:
Inglês
Revista:
Acta Physiologica Sinica
Ano de publicação:
2009
Tipo de documento:
Artigo
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