Fig. 6.

Immunolocalisation of P2X₂R in the cochlea. a Low magnification image of a cross-section of the cochlea from a 100-dB noise-exposed mouse (15 months) showing greatest expression in the hair cells and supporting cells of the organ of Corti, the spiral limbus, Reissner’s membrane and the spiral ganglion cell bodies. The inset shows the absence of immunofluorescence in controls (primary antibody omitted). b, c Higher magnification images of the organ of Corti of young (4 months old) (b) and older (15 months old) (c) mice after exposure to narrow-band noise at 100 dBSPL. Noise exposure caused a significant increase in the P2X₂R expression in the organ of Corti in young animals (3–6 months) (d), which was greatest after 90-dBSPL noise. The intensity of P2X₂R immunostaining was increased in older animals (12–15 months) exposed to noise (E), but only after the 90-dBSPL exposure. Mean ± SEM, **p < 0.01, ***p < 0.001; one-way ANOVA followed by Student’s t test. SG spiral ganglion, SL spiral limbus, OC organ of Corti, IHC inner hair cells, OHC outer hair cells, PC pillar cells, RM Reissner’s membrane