Upregulation of adenylyl cyclase potentiates exocytosis. Whole-cell voltage-clamp recordings were performed in retinal slices that were preincubated for 10 min with Ames (control; black) or containing in addition 10 μm forskolin (orange), a potent activator of adenylyl cyclase. A, The Cm and ICa recordings were performed 4 min after break-in. AII-ACs treated with forskolin produced on average larger ΔCm jumps than controls. Gray bar represents the region where Cm values were averaged. B, Summary plots for ΔCm (left), QCa (middle), and exocytosis efficiency (ΔCm/QCa; right) showing comparisons between AII-ACs for control and 10 μm forskolin datasets. Closed circles represent data from individual AII-ACs. Open circles with error bars represent mean ± SEM. ΔCm was significantly increased when 10 μm forskolin was present in the external solution, whereas QCa did not change significantly. Statistical significance was determined using an unpaired Student's t test: ns, p > 0.05; *p < 0.05.
