Figure 2.

Cochlear and Vestibular projections segregate centrally in the absence of differentiation of hair cells. At E14.5, dye injection into the cochlea and vestibular endorgans show segregation in the cochlear nucleus and vestibular nucleus in control (A) and in Atoh1-cre Atoh1^f/f mice (C) that lack differentiated hair cells. Cochlear projections remain in cochlear nuclei at E18.5 (D), but are smaller compared to control (B). Blue line in (B,D) indicates cochlear nerve diameter as an indicator of reduction spiral ganglion afferents. Cochlear afferents are colored yellow (or separately as red and green when apex and base are individually labeled, respectively), vestibular afferents are colored magenta. AVCN, Anteroventral Cochlear Nucleus; PVCN, Posteroventral Cochlear Nucleus; DCN, Dorsal Cochlear Nucleus; CN, Cochlear Nerve; VN, Vestibular Nerve; CB, Cerebellar fibers; Eff, Efferents; IX, Glossopharyngeal. Bars indicate 100 μm.