Research Paper Volume 11, Issue 23 pp 11541—11564

The local translation of KNa in dendritic projections of auditory neurons and the roles of KNa in the transition from hidden to overt hearing loss

Figure 11. Age-related degeneration of SGN through apoptosis signal. (AD) Immunofluorescence detection of cleaved caspase 3 (red; AB) and caspase 9 (red; C, D) in WT and DKO 5-mo old cochlear sections. SGNs were labeled with neuronal marker TuJ1 (green). The nuclei were stained with DAPI (blue). Scale bar: 20 μm. Increased active caspase 3/9 was seen in DKO cochlear sections. Scale bar = 10 μm. (E) Shown are cochlear sections of in DKO cochleae at difference ages (1-9 mos) assessed for with TUNEL assay (TUNEL-positive in red). Scale bar: 5 μm. (F) Summary histogram showing a significant reduction in SGN size (diameter) between WT and DKO mice at 6-mo old (data from 9 mice each). (G) Age-dependent (1-9 mo) reduction in SGN densities (data from 8-9 mice each). Comparison between WT and DKO mice. (H) Summary data from WT and DKO cochleae at ages indicated, showing increased TUNEL-positive SGNs in 6-9–mo old (data from 8-9 mice each). Significant differences between genotypes were determined using unpaired two-tailed t-test (* p < 0.05, ** < 0.01, *** < 0.001).