Sodium current in periglomerular cells of frog olfactory bulb in vitro.
Brain Res
; 703(1-2): 19-25, 1995 Dec 12.
Article
en En
| MEDLINE
| ID: mdl-8719611
Kinetic properties of the sodium current in periglomerular (PG) cells were investigated by applying whole-cell patch-clamp techniques to thin slices of the frog olfactory bulb. Eight of the cells were intracellularly stained with Lucifer Yellow for precise identification. Under current-clamp conditions PG cells showed rich spontaneous activity at rest. Na current was isolated from other current contributions by equimolar substitution of K+ with Cs+ in the intracellular solution to prevent K-currents, and 100 microM Cd2+ in the external solution to block Ca-current. Depolarisations beyond -40 mV activated a fast transient TTX-sensitive inward current. Once activated, INa declined exponentially to zero following a single exponential. The underlying conductance showed a sigmoidal activation between -40 and +30 mV, with half activation at -17.4 mV and a maximal value of 9.7 nS per neurone. The steady-state inactivation was complete at -30 mV and completely removed at -90 mV, with a midpoint at -56 mV. The activation process could be adequately described by third order kinetics, with time constants ranging from 260 microseconds at -20 mV to 70 microseconds at +50 mV.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bulbo Olfatorio
/
Canales de Sodio
/
Transmisión Sináptica
/
Interneuronas
Límite:
Animals
Idioma:
En
Revista:
Brain Res
Año:
1995
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Países Bajos