Figure 1. K_V1.8^−/− type I hair cells lacked g_K,L, the dominant conductance in mature K_V1.8^+/+,+/− type I HCs.

Representative voltage-evoked currents in (A) a P22 K_V1.8^+/− type I HC and (B) a P29 K_V1.8^−/− type I HC. (A) Arrow, transient inward current that is a hallmark of g_K,L. Arrowheads, tail currents, magnified in insets. For steps positive to the midpoint voltage, tail currents are very large. As a result, K⁺ accumulation in the calyceal cleft reduces driving force on K⁺, causing currents to decay rapidly, as seen in A (Lim et al., 2011). Note that the voltage protocol (top) in B extends to more positive voltages. (C) Activation (G-V) curves from tail currents in A and B; symbols, data; curves, Boltzmann fits (Eq. 1). (D) Fit parameters from mice >P12 show big effect of K_V1.8^−/− and no difference between K_V1.8^+/− and K_V1.8^+/+. Asterisks (here and elsewhere): *, p<0.05; **, p<0.01; ***, p<0.001; and ****, p<0.0001. Line, median; Box, interquartile range; Whiskers, outliers. See Table 1 for statistics.