Fig. 4. Abnormal development of the dentate gyrus in Ngn2 mutant mice. (A,A') Haematoxylin/Eosin staining of hippocampal sections of E18.5 Ngn2 mutant (A') and wild-type (A) embryos show the lack of a morphologically distinct dentate gyrus (asterisk) in mutant brains at this stage. (B,B') Sections through the hippocampus of 1-month-old (P28) Ngn2 mutant (B') and wild-type mice (B) show the absence of the lower blade of the DG (asterisk) in mutant brains. (C,C') High magnification of the upper blade of the wild-type (C) and Ngn2 mutant (C') dentate gyrus. Note the disorganized appearance of the mutant DG. Scale bars: 100 µm.