FIG. 8.

Degeneration of the spiral ganglion neurons following local saline or 3-NP application. Immunostaining for βIII-tubulin (red) and nuclear staining with DAPI (blue) demonstrates no degeneration of spiral ganglion neurons in the apical (A) or basal (B) turn in the cochlea injected with 1 mM 3-NP. In the cochlea injected with 3 (C, D) and 5 mM 3-NP (E, F), severe degeneration of spiral ganglion neurons is observed in the apical turn, while spiral ganglion neurons in the basal turn are preserved. Means of the densities of spiral ganglion neurons are shown in G. Asterisks indicate significant differences to the control group at p < 0.05 (ANOVA with the Scheffe’s test). Bars in G represent standard errors.