Figure 2.

The migratory streams of precerebellar neurons. (A–D) The PN derive from rhombomere (r)6–pr8 precerebellar rhombic lip and take a rostroventral path in the AES to finally settle ventrally in r3 partially and in r4 derived territories. Other precerebellar nuclei such as the LRN and ECN derive from pr7–pr8, migrate ventrally in the PES, cross the midline, and settle contralaterally at more dorsal positions. Migratory streams are shown from lateral (A,C) and ventral (B,D) views as schematic drawings (A,B) and as whole-mount in situ hybridization using the precerebellar neuron marker Barhl1, as a probe (C,D). AES: anterior extramural stream, ECN: external cuneate nucleus, LRN: Lateral Reticular Nucleus, PES: posterior extramural stream, PN: Pontine Nuclei, pr: pseudo-rhombomere, RL: Rhombic lip (C,D from Kratochwil, 2013).