Potassium currents recorded from mature Clrn2clarinet/+ (A, P15) and Clrn2clarinet/clarinet (B, P16) apical-coil OHCs. Currents were elicited by depolarizing voltage steps (10 mV nominal increments) from -144 mV to more depolarized values from the holding potential of -84 mV. Note that the current characteristic of mature OHCs, The size of IK,n, measured in isolation as the deactivating tail currents (difference between instantaneous and steady-state inward currents) for voltage steps from the holding potential to −124 mV, was 545 ± 115 pA, (n=5) in Clrn2clarinet/+ and 595 ± 67 pA, (n=7) in Clrn2clarinet/clarinet OHCs. 