Figure 8.

Apamin, a SK2 channel blocker, nullified the effects of efferent stimulation when added into the perilymph bath solution. The control was performed for a pulse train stimulus (A, stimulus: 200 μA, 1 ms “on,” 10 ms “off”). Efferent modulation imposed no visible effects on the spontaneous bundle oscillations consequent to the blockage of the SK2 channels. B, The average hair bundle oscillation frequency did not change upon efferent activity when apamin was incorporated into the basal bath solution. Circles, triangles, and squares represent oscillation frequencies in standard perilymph, apamin perilymph, and standard perilymph (rinse), respectively. B was averaged from 10 bundles (3 sacculi). Hair bundles originating from the same sacculus were plotted in shades of the same color. Error bars indicate the SDs of individual hair bundle oscillation frequencies.