Fig. 4.

Application of shCaMKKβ via adeno-associated virus transduction significantly protects against noise-induced loss of OHCs and NIHL in FVB/NJ mice. A Application of shCaMKKβ via AAV2.7m8 significantly reduces noise-induced OHC loss. Loss of OHCs was counted along the entire length of the cochlear spiral. Data are presented as means ± SE. The detailed statistical values are listed in Table S1. B Surface preparations show that AAV-shCtrl or AAV-shCaMKKβ mice were immunolabeled with myosin VIIa (red) processed 14 d after the exposure. Images were

taken from the lower basal cochlear turn. Scale bar = 20 µm. C Noise-induced auditory threshold shifts are significantly reduced in AAV-shCaMKKβ mice compared to AAV-shCtrl mice calculated as baseline ABR thresholds subtracted from thresholds measured 14 d after noise exposure for each individual mouse. Data are presented as individual mice ± SD. D Noise-diminished DPOAE amplitudes are significantly reversed by shCaMKKβ application measured 14 d after noise exposure. Data are presented as means ± SD. The detailed statistical values are listed in Table S2; *indicates the p value of the comparison between shCtrl + noise exposure vs shCaMKKβ + noise exposure, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001