Figure 6.

The effect of external K⁺ on the inhibition of the voltage-dependent current in K_2P3.1. (A, B) Steady-state current–voltage relationships for oocytes expressing K_2P3.1 at four external potassium concentrations (0, 4, 20, and 100 mM) under control conditions (A) or after incubation with 1 mM carvone (B). Oocytes were held at −80 mV, pulsed to −135 mV for 30 ms, and then pulsed from −150 mV to 60 mV in 15 mV voltage intervals (mean ± S.E., n = 6–9). (C) The fraction of inhibited current due to carvone application of the total current (Total) and its components: the voltage-independent (VI) and the voltage-dependent (VD) currents. Currents at 60 mV were tested at three external potassium concentrations (4, 20, and 100 mM) (mean ± S.E., n = 6–9). (D–G) Current–voltage relationships for oocytes expressing K_2P3.1 channels at three different external potassium concentrations, as indicated (mean ± S.E., n = 6–9). Currents were measured as in (A). The voltage-independent (D, E) and the voltage-dependent (F, G) fractions of the current were calculated as in Figure 1C and are presented individually. Measurements were performed before (D, F) and after (E, G) application of 1 mM carvone. *p ≤ 0.05, ns, not significant.