Ethanol does not alter the parameters associated with closed to open conformational change. (A) Representative unitary current recordings evoked from I/O patches in nominal zero Ca²⁺_i, with membrane patches held at the indicated voltages. Recordings were obtained before (left) and immediately after (right) patch exposure to 50 mM ethanol. Arrows indicate the baseline (all channels in nonpermeant states). (B and C) Mean log Po-V relations over a wide range of voltages in the presence and absence of 50 mM ethanol. Below 80 mV, data points were obtained from unitary current recordings; above 80 mV, data points were obtained from macroscopic current recordings in nominal zero Ca²⁺_i. Po-V data at far negative voltages were fitted with Eq. 2 to determine L₀ and z_L. Best-fit parameters (±95% confidence interval) are listed in the corresponding graphs. On average, patches contained 450 channels. n = 11; each patch was excised from a different cell. Data are expressed as mean ± SEM.