FIGURE 5.

β subunit regulation of heterologously expressed Na_v1. 7 channels. Shown are whole-cell Na⁺ currents of HEK293 cells stably expressing the Na_v1.7 channels. Currents were elicited by depolarizing voltage pulses between −90 and +50 mV from a holding potential of −120 mV. A–C, representative Na⁺ currents of Na_v1.7 channels expressed alone (A) or coexpressed with β₁ (B) or β₃ (C) subunits. D, plot of the peak current density (picoamperes/picofarads) of Na_v1.7 channels alone or coexpressed with β subunits (β₁–β₄). Data are the means ± S.E. of 13 (Na_v1.7), 26 (β₁), 9 (β₂), 18 (β₃), and 8 (β₄) determinations.