Figure 6

The RL generates EGFP+ cells that are not precursors of DCN neurons (E12.5–E13.5). A: lower power view of a future Cb hemisphere at E12.5 illustrating the pattern of EGFP expression in two seemingly related cell populations: tightly packed bipolar cells in the RL, and isolated cells with a unipolar shape and a leading process contacting the pial surface in the nascent EGL, which is characteristic of migrating GPs (arrows). B, C: higher power views of the E12.5 RL, illustrating the localisation of EGFP+ Pax6+ cells in the medial (B), and lateral (C), portion of the RL, and the presence of Pax6+ EGFP- cells in the nascent EGL (arrowheads). Nuclei of the cells in which EGFP/Pax6 co-expression is obvious are marked by colored dots, EGFP+ Pax6- cells by asterisks. The long branching processes emitted by the RL EGFP+ cell population are better visualized in C. D: at E13.5 and on coronal sections, the Olig2+ NTZ (1) and EGFP+ EGL (2) constitute clearly distinct populations.