Mechanisms of Hearing Loss after Blast Injury to the Ear
(A) Plastic embedded sections of control mice and mice seven days after blast exposure. There was a significant reduction of spiral ganglion neurons (SGNs) in blast-exposed mice compared to controls (non-paired Student's t-test, p = 0.013). SGNs were identified by their larger nuclei and prominent nucleoli. (B) Summed confocal Z-stack images of the apical turn of the cochlea in control and mice seven days after blast exposure. The number of synaptic ribbons (red punctate labeling) under the IHCs and the OHCs was reduced after blast exposure (non-paired Student's t-test, p<0.0001 for both). (C) Representative paraffin embedded cochlear cross-sections stained with DAPI from a control mouse, a mouse one day after blast exposure, and a mouse seven days after blast exposure. The boxes highlight the modiolus, which was expanded for the immunolabeling studies in (D). (D) IBA1 expression was stronger in mice one and seven days after blast exposure. Scale bars: A-50 µm, B-20 µm, C-200 µm, D-200 µm.