Figure 5. L-type Ca²⁺ channels contribute to activation of the ADP but have little effect on the AHP.

A, addition of 10 μm nifedipine abolished the ADP revealing an AHP after one AP (a) and reduced the ADP without affecting AHP amplitude after a train of 13 APs (b). B, averaged inward currents from nine cells in apamin were reduced when nifedipine was added. C, averaged outward currents from 11 cells in the presence of 9AC showed, when nifedipine was added, a small decrease after a single AP (a) and a change in the time course after a train of APs (b).