Phase3: repolarization This proceeds more slowly than dose depolarization(phase 0). Phase 4: The interval from the completion of repolarization until the beginning of the next action potential Fast response 膜电位 AP 0 -80 b 4 ERP 100200300Phase 3 ：repolarization This proceeds more slowly than dose depolarization (phase 0). Phase 4 : The interval from the completion of repolarization until the beginning of the next action potential