Fig. 6. Tangential migration from MGE and POA. (A-D) Cell tracing by DiI injection. Labeled cells from E13.5 MGE after 48 hours in culture can migrate to the cortex. (A,C) Bright-field images of a wild-type (A) and a mutant (C) slices with DiI crystals placed in the MGE. (B,D) Fluorescent images of the region boxed in A and C, respectively; white arrowheads show migrating cells in the cortex of wild-type and mutant embryos. (E-H) Immunohistochemistry for calbindin on coronal sections at E13.5 wild-type (E,F) and Vax1^-/- embryos (G,H). (F,H) High-magnification images of the region boxed in E and G, respectively; black arrows indicate labeled cells in a tangential orientation. Clear leading processes are present. Arrows in G indicate an aberrant accumulation of calbindin-positive cells in the area of the MGE and POA. CX, cortex; LGE, lateral ganglionic eminence; MGE, medial ganglionic eminence; POA, preoptic area. Scale bars: 100 µm.