Ethanol responses of β3- or β4-containing BK currents mimic those of homomeric BK (cbv1) channels. (A and C) V_0.5 versus [Ca²⁺]_i plot showing that the activation to inhibition crossover for ethanol effect on cbv1+β3 (A) and cbv1+β4 channel complexes (C) occurs at ∼20 µM Ca²⁺_i, as found for homomeric cbv1 exposed to ethanol (see Fig. 2 D). (B and D) Bar graphs representing ethanol-induced change in V_0.5 values from cbv1+β3 (B) and cbv1+β4 channel complexes (D) obtained at 0.3 µM and 100 µM Ca²⁺_i. n = 3–7 patches; each patch was excised from a different cell. *, different from control (P < 0.05); **, different from control (P < 0.01). Data are expressed as mean ± SEM.