Fig. 3

a Schematic showing imaging of utricular HCs during vibration in pitch/roll axis (top). Hair-bundle polarity (arrowheads) and vibration axes (double-headed arrows) (bottom). The same orientation applies to (b), (c), (e), and (f). b Example of HC responses to vibration stimulus in pitch and roll axes (see Supplementary Movie ⁴). Vibration time course (top). Sequential images showing mean ΔR/R₀ responses during the time period “i” to “iv” (left). Average of 8 trials. Organ-average of the mean ΔR/R₀ responses during the time period “iv” in 6 utricles (right). Scale bar: 10 μm. c Example of vibration responses per HC. The same utricle shown in (b). Responses to pitch (left) and roll (right) vibration. HC location (top). Vibration time course (middle). ΔR/R₀ per HC (bottom). R/C: rostrocaudal; M/L: mediolateral. d Mean ΔR/R₀ time course in HC groups in (c) (top). Pitch: 45 cells activated; 38 cells not activated. Roll: 38 cells activated; 45 cells not activated. Mean of the 6 utricles (bottom). Deviation (SEM) is shown in gray. Vibration time course is the same as in C. Scale bar: 10% ΔR/R₀. R/C: rostrocaudal; M/L: mediolateral. Example (e: the same utricle shown in [b]) and summary (f) of HC response vectors. Orientation of bars indicates stimulus direction. Length of bars indicates ΔR/R₀ amplitude (e) or mean amplitude per grid that is larger (magenta) or not larger (gray) than 5% (f, see “Methods”). Black scale bar: 20% ΔR/R₀. Gray scale bar: 10 μm. Source data are provided as a Source Data file.