Figure 3
From: Paroxysmal extreme pain disorder M1627K mutation in human Nav1.7 renders DRG neurons hyperexcitable
The M1627K mutation alters inactivation properties of Na v 1.7. A, Normalized peak current-voltage relationship for WT (filled squares, n = 11) and M1627K (open circles, n = 15) channels. Cells were held at -100 mV and currents were elicited with 50 ms test pulses to potentials ranging from -80 to 40 mV. B, Time constants for tail current deactivation at repolarization potentials ranging from -40 to -100 mV for WT (filled squares, n = 8) and M1627K (open circles, n = 9) Nav1.7 channels. Time constants were obtained with single exponential fits to the deactivation phase of the currents. C, Comparison of steady-state fast-inactivation for WT (filled squares, n = 11) and M1627K (open circles, n = 15) Nav1.7 channels. Currents were elicited with test pulses to 0 mV following 500 ms inactivating prepulses. D, Comparison of slow-inactivation for WT (filled squares, n = 3) and M1627K (open circles, n = 4) Nav1.7 channels. Slow inactivation was induced with 10 s prepulses, followed by 100 ms pulses to -120 mV to allow recovery from fast-inactivation. A test pulse to 0 mV for 20 ms was used to determine the fraction of current available.