Figure 4.

Voltage-dependence of activation and inactivation of Na_v1.2/Na_v1.8 chimeras. Conductance-voltage relationships (G-V) for activation and steady-state inactivation of the Na⁺ conductance were obtained for chimeras 8822 (A), 8288 (B), 8/288 (C), 8882 (D) and 2/8822 (E). Voltage-dependence of activation was determined by applying depolarizing pulses from a holding potential of −80 mV to +40 mV in 10 mV increments. Steady-state inactivation was determined using a two-pulse protocol where oocytes were depolarized with a test pulse to +10 mV from conditioning pre-pulse potentials (550 ms) ranging from −110 mV to +50 mV. Activation and inactivation curves were fitted with a single Boltzmann function (see methods). Data represent mean ± SEM for 8822 (n≥ 15), 8288 (n≥ 11), 8/2288 (n≥ 10), 8882 (n≥ 16) and 2/8822 (n≥ 16) (see Table 1).