Time Courses of Changes in Phospho- and Total- MAP Kinases in the Cochlea after Intense Noise Exposure
Figure 6
Immunolocalizations of phospho-JNK, phospho-p90 RSK, and phospho-p38 MAPK at 3 h and 48 h after the noise exposure.
At 3 h post-noise exposure, cytoplasmic and nucleoplasmic immunoreactivity to phospho-JNK was observed in the spiral ligament (B), the sensory and supporting cells of the organ of Corti (E; OHC, outer hair cells; IHC, inner hair cells; SC, supporting cells) and the spiral neurons (H). In the spiral ligament, phospho-JNK immunoreactivity was more evident in the type I and II fibrocytes (B, arrow) than in the type III and IV fibrocytes (B, arrowhead). At 3 h post-noise exposure, immunoreactivity to phospho-p90 RSK was demonstrated in the spiral ligament (C) and in the sensory and supporting cells of the organ of Corti (F). Phospho-p90 RSK immunoreactivity was absent in the spiral neurons at this time point (I). At 48 h post-noise exposure, immunolocalization of phospho-JNK was shown in the cytoplasm and nucleoplasm of the spiral neurons (K). Phospho-p38 MAPK immunoreactivity in the cytoplasm and nucleoplasm was also demonstrated in the spiral neurons (L) at 48 h. The sections of negative controls resulted in no staining in any structures and time points (A, D, G, J). Scale bars indicate 20 (D, E, F, G, H, I, J, K, L) and 40 (A, B, C) μm.