Fig. 5: MET currents in IHC and OHC stereocilia bundles.

a MET current in IHCs from control (mc), Pz1^MU, and Pz2^MU mice at P10 in response to fluid-jet deflection. HCs were held at −80 mV. Bundle deflection was elicited with 0.1–0.9 V pressure clamps in 0.1-V steps. For clarity, a few traces were omitted. b OHC traces from mc, Pz1 and Pz2 double mutant (mc-Pz1-2^MU). c Maximum IHC and OHC current (mean ± SD), mc, 493 ± 255 pA (n = 30 IHC) from seven mice, mc-Pz1^MU was 53 ± 54 pA (n = 30 IHCs) from nine mice, and mc-Pz2^MU was 58 ± 58 pA (n = 30 IHCs) from nine mice. One-way ANOVA, F(2,87) = 82, p = 1.1 × 10⁻²⁰ mc vs. mc-Pz1^MU, p = 1 × 10⁻²⁵; mc vs. mc-Pz2^MU, p = 1 × 10⁻²³; mc-Pz1^MU vs mc-Pz2^MU, p = 1.0. For OHCs mc, 484 ± 263 pA (n = 32 OHCs) from eleven mice, mc-Pz2^MU 58 ± 52 pA (n = 32 OHCs) from eight mice, and mc-Pz1-2^MU (15 ± 15 pA (n = 29 OHCs)) from 6 mice. One-way ANOVA, F(2,90) = 85, p = 2.2 × 10⁻²¹ mc vs. mc-Pz2^MU, p = 1 × 10⁻²⁶; mc vs. mc-Pz1-2^MU, p = 1 × 10⁻³⁵; mc-Pz2^MU vs mc-Pz1-2^MU, p = 0.6. Box plot, maxima, and minima are in (—), mean (□), and 99% and 1% are (X). d Displacement-response relationship for mc (black) vs. mc-Pz1^MU () and mc-Pz2^MU (). e Normalized displacement-response relationships fitted with a two-state Boltzmann function control (black) and a three-state function for mc-Pz1^MU () and mc-Pz2^MU (). f Displacement-response relationships fitted with a two-state Boltzmann function for OHC MET current (black) g–i Currents elicited with a 40-Hz sinusoidal deflection of P10 apical IHC mc with and without BAPTA. Positive-voltage evoked- inwardly directed current. BAPTA treatment reduced current by ~10-fold. Post-BAPTA currents had reversed polarity. i Summary data for BAPTA-mediated residual currents (RPI) in IHCs in mc-Pz1^MU and mc-Pz2^MU in P10 mice. The numbers of IHCs recorded are indicated in parenthesis, and the ones with measurable RPI are indicated without parenthesis. Data were obtained from at least 4 different mice in each group. Values in mean ± SD, control 21 ± 3 pA (n = 16); mc-Pz1^MU 7 ± 1 pA (n = 11); mc-Pz2^MU 8 ± 1 pA (n = 11). One-way ANOVA F(2,35) 12, p = 1.4 × 10⁻⁴; control vs. mc-Pz1^MU, p = 6.3 × 10⁻⁴; control vs. mc-Pz2^MU, p = 0.001; mc-Pz1^MU vs. mc-Pz2^MU, p = 0.98. Source data are provided as a Source Data file.