FIGURE 3.

Prestin-dependent motility. (A) Relative length (L, blue), longitudinal section area (A, red), and estimated prestin-dependent length changes calculated from the area values (A², green) in one representative OHC that underwent square pulse stimulations. The 10 OHCs tested in this experiment showed similar responses. Values were normalized to those during V_H = −70 mV and plotted against V_H. Note that actual L changes fitted very well with predicted area-triggered length changes (A²). (Inset) Voltage-sensitive nonlinear capacitance measured in this cell. (B) Experiments with ramp stimulation. Again, as shown in the response of one representative OHC out of four tested, actual L changes fitted very well with predicted area-triggered length changes (A²). No differences were evident in the response of the four tested OHCs. (C) The plot of voltage-induced length changes (x axis) to the square value of voltage-induced area changes (A², y axis) in the same representative cell described in panel B. The values were very similar (y ≈ ξ). Fitting parameters are: y = 1.1x − 0.09, R² = 0.97.