Effects of cAMP on exocytosis are independent of AII-AC gap junction coupling. Whole-cell voltage-clamp recordings in AII-ACs from Cx36−/− mice performed using an internal solution containing 1 mm cAMP. A, Average Cm and ICa responses to a 100 ms depolarizing pulse. Recordings were performed before 1 min (blue) and at 4 min (red) after break-in. Cm jumps are larger after 4 min, with no changes in ICa traces. Gray bar represents the region where Cm values were averaged. B, Summary plots for ΔCm and QCa showing pairwise comparisons between the time periods after break-in for each recording. Closed circles represent data from individual AII-ACs. Open circles with error bars represent mean ± SEM. ΔCm significantly increase after 4 min without any corresponding changes in QCa. Statistical significance determined using a paired t test: ns, p > 0.05; ***p < 0.001.
