Cl
- current in GABA-sensitive neurons of the frog dorsal root ganglia was separated from other Na
+, Ca
2+ and K
+ currents using the suction pipette technique which allows internal perfusion and current clamp. Adequacy of the internal perfusion technique was assessed from the reversal potential for GABA-induced Cl
- current (E
GABA) at various intracellular Cl
- concentrations. E
GABA was equal to the Cl
- equilibrium potential (E
c1) and behaved as a simple Cl
- electrode following changes of external and internal Cl
- concentrations ([Cl]
0 and [Cl]
1). E
GABA changed by 58 mV for a tenfold change in either [Cl]
0 or [Cl]
i at constant [Cl]
0 or [Cl]
1, respectively. GABA-induced Cl
- conductance increased dose-dependently. In addition, single Cl
- channel current (i
cl) and conductance (γ
c1) were estimated from the Cl
- current fluctuation by using both power spectrum and amplitude histogram methods, and the theoretical values were compared with those measured directly by a conventional inside-out patch clamp technique.
抄録全体を表示