Fig. 3.
Effects of the β1 subunit on the kinetics of Nav1.7 and Nav1.8 inactivation. Whole-cell sodium currents of Nav1.7 and Nav1.7+β1 sodium channels were elicited by a depolarizing step from −100 to −20 or +20 mV. Currents were normalized to facilitate comparison of the kinetics. A, At −20 mV the time constants of current decay were 19.8 ± 3.6 msec (n = 6) and 1.8 ± 0.2 msec (n = 6) for Nav1.7 and Nav1.7+β1, respectively.B, Nav1.8 and Nav1.8+β1 currents were elicited by a step depolarization to +20 mV and had decay time constants of 4.3 ± 0.2 msec (n = 6) and 2.6 ± 0.1 msec (n = 6), respectively. Dashed linesare the zero current levels.