Increased seizure duration and slowed potassium kinetics in mice lacking aquaporin-4 water channels.
Glia
; 53(6): 631-6, 2006 Apr 15.
Article
en En
| MEDLINE
| ID: mdl-16470808
ABSTRACT
The glial water channel aquaporin-4 (AQP4) has been hypothesized to modulate water and potassium fluxes associated with neuronal activity. In this study, we examined the seizure phenotype of AQP4 -/- mice using in vivo electrical stimulation and electroencephalographic (EEG) recording. AQP4 -/- mice were found to have dramatically prolonged stimulation-evoked seizures after hippocampal stimulation compared to wild-type controls (33 +/- 2 s vs. 13 +/- 2 s). In addition, AQP4 -/- mice were found to have a higher seizure threshold (167 +/- 17 microA vs. 114 +/- 10 microA). To assess a potential effect of AQP4 on potassium kinetics, we used in vivo recording with potassium-sensitive microelectrodes after direct cortical stimulation. Although there was no significant difference in baseline or peak [K(+)](o), the rise time to peak [K(+)](o) (t(1/2), 2.3 +/- 0.5 s) as well as the recovery to baseline [K(+)](o) (t(1/2), 15.6 +/- 1.5 s) were slowed in AQP4 -/- mice compared to WT mice (t(1/2), 0.5 +/- 0.1 and 6.6 +/- 0.7 s, respectively). These results implicate AQP4 in the expression and termination of seizure activity and support the hypothesis that AQP4 is coupled to potassium homeostasis in vivo.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Potasio
/
Convulsiones
/
Desequilibrio Hidroelectrolítico
/
Encéfalo
/
Canales de Potasio
/
Acuaporina 4
Límite:
Animals
Idioma:
En
Revista:
Glia
Asunto de la revista:
NEUROLOGIA
Año:
2006
Tipo del documento:
Article
País de afiliación:
Estados Unidos