Fig. 1.

Reelin in early marginal zone. A, Stage 16, 5 GW. The first Reln-ir neurons appear at the outer aspect of the prospective neocortical neuroepithelium, in a narrow cell-sparse MZ. In this and the following microphotographs, the dashed line marks the border of the MZ and VZ. Scale bar, 25 μm.B, Stage 16/17, 5.5 GW. The VZ occasionally contains weakly Reln-ir cells (arrowheads), which seem to ascend to the MZ. Scale bar, 25 μm. C, Stage 17, 5.5 GW. Reln-ir neurons in the MZ increase in number. Scale bar, 50 μm.D, Stage 18, 6.5 GW. In rostral cortical areas, Reln-ir neurons lie now at different distances from the pial surface. Scale bar, 50 μm. E, Stage 17/18, 6 GW. In addition to Reln-ir neurons in the MZ, a few weakly immunostained cells (arrowheads) are present in the VZ, arranged into columns. Scale bar, 50 μm. F, Same case as inE, at a more caudal level, where Reln-ir neurons in the MZ are less numerous. Note positive cells in the deep VZ. Scale bar, 25 μm.