Fig. 5. Tangential migrations in the cortex. (A,B) Dlx2-expressing zone in the wild type (A) (high magnification in a) from which cells migrate into the cortex (arrowhead in A). In the Psen1 mutant (B), the Dlx2-positive domain (high magnification in b) is abnormal, and migration into the cortex appears enhanced (arrowhead in B). (C,D) Gad67-positive cells engage in tangential migration through deep layers in the wild-type (C), but aggregate superficially in the mutant (arrow in D). Ventral quadrant view of coronal sections through E17.5 embryos processed for in situ hybridization.