Fig. 6.

DTT-mediated decrease is independent of L-type Ca²⁺ channel function. (A) Time course of the change in the normalized sAHP amplitude recorded from aged animals that were incubated with nifedipine (n = 4), followed by application of DTT. (B) Time course of the change in the normalized sAHP amplitude in the aged animals that were incubated with nifedipine (n = 6) for ≥45 min prior to the application of DTT for 30 min. Calibration bars: 200 ms, 10 mV. (C) Representative traces illustrating the change in the AHP of aged animals under control condition (black trace), and at the end of a 20 min application of nifedipine (gray trace) and at the end of 30 min application of nifedipine+DTT (black trace). Inset: Magnified representation of change in the aged AHP under control condition, nifedipine, and nifedipine + DTT.