Fig. 3. Development of rested-state inactivation of I_Na in ventricular myocytes of crucian carp, rainbow trout and burbot hearts. (A) Voltage protocol and representative recordings of I_Na; (B) results shown as means ± S.E.M. (N=6–13). Increased duration of the prepulse at –60 mV reduces I_Na elicited by the test pulse to –20 mV for 30 ms.