Figure 8.

Rapid turgor pressure changes induce membrane tension with accompanying relaxations in C_m. (A) Photos of an OHC at different time points during a 1.8 kPa pressure step. C_m relaxation and longitudinal strain ((L − δL)/L) are plotted beneath. Green bar indicates pressure delivery to the cell. Note the majority of strain occurs before C_m relaxation begins. (B) Another cell. Color coded C_m traces induced by combinations of voltage ramps (1 and 2), voltage steps (3) and pressure steps. Single exponential fits of the C_m relaxations due to 1.4 (dark green), 1.6 (blue), and 1.8 (purple) kPa steps were 1.01, 0.88, and 0.16 s, respectively. (C) C-V plots obtained 2 s after onset of pipette pressure steps. Voltage was corrected for R_s effects that ranged from 1.7–4.5 MΩ during the pressure changes. (D) Boltzmann parameters V_pkcm and z as a function of pressure.