Fig. 7: PAO-induced effects on OHC electromotility, lipid mobility, and microphonics.

a In comparison with DX-52-1 (Fig. 4a), changes in electromotility induced by PAO are small. Here, images acquired during positive and negative currents were superimposed. b Time course of electromotility amplitude (blue circle) in a preparation showing minor increase after PAO injection. The vertical line at time zero indicates the time of injection. Data were normalized to the average electromotility amplitude recorded before injection. c The average electromotility amplitude increased non-significantly after the PAO injection. Data from 30 (PAO) individual preparations. The acoustic stimulus was a 220 Hz tone at 80 dB with current stimulus of 10 µA. d FRAP experiment showing no change in the stereocilia bundle morphology seen before and after PAO injection. e Normalized traces of the fluorescence intensity during the recovery before and after PAO injection in an example preparation. f Fitting the experimental data to single-phase exponential fit model showed faster recovery of the bundle fluorescence with reduced τ_1/2 after PAO injection on average for 22 preparations. g No change in the cell somatic membrane morphology before and after PAO injection. h Normalized traces of the fluorescence intensity showing no change in the membrane dynamics before and after PAO injection in an example preparation. i Fitting the experimental data to single-phase exponential fit model showed a non-significantly faster recovery of cell membrane fluorescence with reduced τ_1/2 after PAO injection (n = 9). j Tuning curves for the CM potential before and after 1 mM PAO injection in an example preparation. k Normalized peak amplitude of the time course of the CM potential showing substantial and irreversible decrease 10–15 min after PAO injection in an example preparation. The vertical line indicates the time of injection of PAO. l Comparison of CM potential amplitude before and after PAO injection (n = 33), which reduced significantly for experiments in panel (k). Data are mean ± s.d. All data sets were normalized to the data recorded before the injection. ****P < 0.0001; **P < 0.01; *P < 0.05; n.s., not significant; two-tailed paired t-test.