(A) Elevated levels of Hes5 after noise exposure were diminished in response to LY411575 treatment and reached the pre noise level. Without inhibitor, expression levels of Hes5 in the cochlea increased 1 d after noise exposure and remained elevated compared to the pre noise level for up to 2 d. Samples for qRT-PCR were taken before exposure to noise (pre noise), at the time (day 0) of drug treatment (post noise), at day 1 of drug treatment (d 1), day 3 of drug treatment (d 3), and day 7 of drug treatment (d 7). mRNA expression levels were calculated relative to the pre-noise level.
(B) Treatment with LY411575 significantly increased the expression of Atoh1 compared to the opposite, untreated ear 1 d after noise exposure. Increased levels were detected 1 d after drug treatment (d 1) and remained elevated 3 d after drug treatment (d 3; n = 9 in each group. Error bars are standard error of the mean. Asterisks indicate p < 0.05.