sentence: ( 4 ) Characteristic of H ‐ current cells was the coincidence of a sag ‐ potential or current ( > 25pA ) and an AHP ( 2.5 – 19 mV ) that peaked ~ 55 msec following termination of a 200pA depolarizing current ; however , neurons were assigned to the H ‐ current group based on these properties regardless of their firing pattern .