Representative histological images of the Nissl-stained basal regions and distortion product otoacoustic emissions (DPOAE) results. (A) General views of the cochlear basal turn (a,f) for NF (n = 3) and FD mice (n = 3) 10-months old. Detailed views of the organ of Corti (OC; b,g), where collapse of the inner and outer pillar cells is observed in both dietary groups (#) and the presence of outer hair cells in the NF (arrows) and their absence in the FD group (***) are indicated. Additional subpanels show detailed views of the stria vascularis (StV; c,h) with melanin granules in both dietary groups (arrows); spiral ligament (Spl; d,i) and cochlear ganglion (CG; e,j). Bar scale: 150 μm (a,f); 25 μm (remaining panels). (B) DPOAE analysis at 2- (2M; NF n = 9 and FD n = 10) and 10-months (10M; NF n = 9 and FD n = 5) of age; DP thresholds (a) and 2f1-f2 amplitudes (b) are shown (mean ± SEM). *p < 0.05.