Figure 8.

Electrophysiological evaluation of 21a in HEK-Na_v1.6 cells in the absence of FGF14. (A) Representative traces of transient Na⁺ currents recorded from HEK-Na_v1.6 treated with 0.1% DMSO (black) or 10 μM 21a (blue) in response to varying voltage stimuli ranging from −100 mV to + 60 mV(inset). (B) Comparison of tau of fast inactivation at −10 mV between the indicated experimental groups. (C) Current-voltage relationship for HEK-Na_v1.6 treated with 0.1% (black) or 10 μM 21a. (D) Comparison of peak current density among the indicated experimental groups. (E) Conductance-voltage relationship for HEK-Na_v1.6 treated with 0.1% DMSO (black) or 10 μM 21a. (F) Comparison of V_1/2 of Na_v1.6 channel activation between the indicated experimental groups. (G). Comparison of the voltage-dependence of steady-state inactivation between HEK-Na_v1.6 treated with 0.1% DMSO (black) or 10 μM 21a. (H) Comparison of V_1/2 of the steady-state inactivation of Na_v1.6 channels between the indicated experimental groups. (I) Effects of 0.1% DMSO (black) and 10 μM 21a (blue) on the long-term inactivation (LTI) of Na_v1.6 channels. LTI was characterized by plotting the fraction of Na_v1.6 channels available as a function of depolarization cycle. See experimental section for additional information describing electrophysiological protocols employed and corresponding data analyses. (J) Bar graph summary of (I). Results are expressed as the mean ± SEM. A Student’s t-test was used to determine statistical significance. . **, p < 0.005; ***, p < 0.0005.