Fig. 4

PP121 switched the L-VDCC, NSCC and BK⁺ currents. A L-VDCC currents were triggered under a stepped voltage ranging from -70 to + 40 mV in 10 mV increments every 50 ms. B L-VDCC currents could be eliminated by 10 μM nifedipine or 56 µM PP121. C The current-voltage curve is presented (n = 5/5 mice). D NSCC currents were recorded with a 500 ms ramp from − 80 to + 60 mV in 500 ms. E 10 μM nifedipine, 10 μM NA and 10 mM TEA were employed to isolate NSCC currents. Then, 100 μM ACh-induced NSCC currents were inhibited by 40 μM PP121 (n = 5/5 mice). The data at − 70 mV were used to plot current-time traces. F The net ramp currents at times a, b, and c from − 80 to + 60 mV. G BK currents were recorded under ramp voltages ranging from − 80 to + 80 mV at 10 mV increments. H BK currents could be erased by a specific blocker, 1 μM PAX, while 40 μM PP121 strengthened the currents. I A current-voltage curve was constructed based on the results of 5 cells from 5 mice. *p < 0.05; **p < 0.01; ***p < 0.001