Fig. 6: PAO-induced effects on OHC stereocilia sound-evoked motions.

a Time-resolved confocal image of an OHC stereocilia bundle showing the morphology is intact before and after the injection, except for a small change in the brightness of the fluorescent dye. b Representative data showing change in sound-evoked motion of the bundle tip (red) and base (blue) before and after PAO injection. The stimulus was a pure tone at 220 Hz and 80 dB sound pressure level. c–e Averaged change of the bundle motion at the base of outer hair cell stereocilia (blue bar), at their tip (red bar), and deflection (green bar) are shown. Significant decrease in tip and base motion resulting in a change in the bundle deflection. Data were normalized to the base trajectory amplitude recorded before the injection. Mean data from 35 (PAO) individual preparations ± s.d. f Example time course of deflection amplitude of outer hair cell stereocilia bundle (blue circle) showing decrease after PAO injection. The vertical line at time zero indicates the time of injection of PAO. Data were normalized to the average trajectory amplitude recorded before injection. g High-resolution confocal images of stereocilia in preparations treated with PAO or vehicle show no detectable morphological difference. ****P < 0.0001; **P < 0.01; *P < 0.05; n.s., not significant; two-tailed paired t-test.