α-chloralose opens the chloride channel of frog isolated sensory neurons

Abstract

The effect of α-chloralose on the sensory neurons isolated enzymatically and mechanically from frog dorsal root ganglia was studied using a suction-pipette technique. The threshold concentration of α-chloralose was around 3 x 10^-5 M and the current produced by α-chloralose saturated at the concentration of 3 x 10^-3 M or more. The dose-response curve for α-chloralose provided aK_a value of 6 x 10^-4M and a Hill coefficient of 1.8. The reversal potential of the response elicited by α-chloralose was close to the equilibrium potential for Cl^- (E_Cl), indicating that the current was carried through Cl^- channels. The current-voltage relationship indicated that there was little voltage dependence in the α-chloralose-induced response. The analysis of the variance of the α-chloralose-induced Cl^- current fluctuations showed two types of the receptor-ionophore complexes with different channel conductances.