Activation of the gate mutant F192M by receptor stimulation and halothane is more than additive. A, sample TEVC recording from an oocyte expressing Kir3.1/Kir3.2(F192M)/hM2 and its response to ACh and halothane applied together or separately. HK, high potassium. B, bar graph summary for current induction by co-application of halothane and ACh as compared with the combined effect of the two applied separately. The value for the two co-applied is significantly larger that than the effects of the two added separately (* denotes p < 0.05, paired t test, n = 8).