Power Efficiency of Outer Hair Cell Somatic Electromotility
Figure 2
Voltage dependent capacitance and axial stiffness.
A) Model predictions for the nonlinear capacitance based on the Boltzmann piezoelectric distribution compared to data from Kakehata & Santos-Sacchi [38] for a ∼50 micron long OHC under conditions of zero load. The capacitance exhibits a linear component plus a nonlinear (voltage dependent) component. Dashed curves show the effect of varying the piezoelectric coefficient by ±25%. B) The model predicts a parabolic relationship between the nonlinear component of capacitance and the peak isometric force as the membrane potential is traversed from −200 to +130 mV (same cell). All subsequent results are for small (linearized) forces and movements about a membrane potential of −78 mV. C) Compliance predicted by the model (solid line) is shown vs. cell length in comparison to data (symbols) from Frank et al., [48].