Intracochlear neomycin administration resulted in a complete loss of hair cells and supporting cells in the basal turn, forming a flat epithelium. A few looping auditory fibers are seen in the basilar membrane area of un-injected ears (A), whereas significantly more radial fibers are seen in neurotrophin injected ears (B: NT-3 vector, C: BDNF vector). Green = Actin; Red = Neurofilament 200 kDa. Scale Bar = 50 μm.

Systemic administration of K&F resulted in a complete loss of hair cells in the basal turn and patches of surviving supporting cells. The few neural fibers seen in the basilar membrane area of un-injected ears make short loops (A, B). In contrast, neurotrophin vector receiving ears have significantly more neural fibers, which also extend farther from the habenula (C, D: NT-3; E, F: BDNF). Neural fibers did not appear to re-grow in regions of surviving supporting cells (D, F). A prominent re-growth of neural fibers is seen in regions devoid of supporting cells (C, E). Green = Actin; Red = Neurofilament 200 kDa; Scale Bar = 50 μm.