Figure 1

Schematized NM-NL circuit. (A) Illustration of a dissected chick embryo brainstem at E10 with auditory nuclei (including NM and NL) outlined bilaterally and the coronal plane of section for (B) indicated with a dashed line. (B) Coronal section of an E10 chick auditory brainstem with bisbenzimide nuclear staining. Bilateral projections from a single representative right-sided NM cell are schematized. Ipsilateral NM axon contacts dorsal NL neuropil with divergent branches of similar length, while contralateral NM axon contacts ventral NL neuropil with a delay line. Note the absence of cells in the neuropil surrounding NL cells where NM axons synapse. Scale bar = 0.5 mm in (A) and 100 μm in (B). VIII = eighth cranial (vestibulocochlear) nerve.