Fig. 7.

EtOH-induced reduction of native DSM single BK channel activity under the condition of highly elevated intracellular [Ca²⁺]. A: representative recordings from a single experiment (inside-out configuration at +40 mV) with K⁺ solution containing ∼10 μM free [Ca²⁺] for the intracellular (bath) compartment before and after the application of 0.3% EtOH. Shown are also all point-histograms (analyzed interval of 30 s) for each condition. C and the dotted line depict the closed channel state, arrowheads the open channel states, and the parallel dashed lines breaks in the y-axis as there were no single channel events detected within the limits. B and C: Summaries for single BK channel open probability (B) and single BK channel current amplitude (C) in 8 inside-out excised patch experiments showing a significant decrease in the open probability, but no effect on the single BK channel unitary amplitude following the application of 0.3% EtOH in the presence of ∼10 μM intracellular free [Ca²⁺] (N = 4); *P < 0.05; ns, nonsignificant effect (P > 0.05) vs. pre-EtOH control values.