The innervation of sensory epithelia is shown in 6-month old Brn3c null mutant mice. Compared to P8 animals there is a further reduction of fiber density to vestibular sensory epithelia, but fibers can be traced to all sensory epithelia (a,b). Transcellular labeling with DiI (b) suggest contacts between these afferents and immature hair cells. The cochlea shows a much reduced density of radial bundles, even in the apex (c,d). However, spiral sensory neurons are present in Rosenthal's canal (c,d) and fibers extend to the organ of Corti where they form longitudinal tracts in the immature epithelium. Bar indicates 100 μm.
Xiang et al. BMC Neuroscience 2003 4:2 doi:10.1186/1471-2202-4-2