Fig. 7. ErbB4 signaling is essential for the extension of leading process on migrating cerebellar rhombic lip cells. (A) Cerebellar explants electroporated with EGFP were pre-cultured for 24 hours, before treatment with 100 µM AG1478, an RTK inhibitor, for 2 hours, followed by fluorescent in situ imaging. Fluorescent images were captured every 2 minutes for 2 hours, and images from 0, 40, 80, 120 minute time points are shown. Inhibition of RTK suppressed the protrusion formation at the TLP. Bar, 10 µm. (B) Expression of dominant-negative mutant ErbB4IC inhibited extension of TLPs (see supplementary material Movie 16).