Figure 2.

Absence of the neurogenic cluster at the fimbriodentate junction. (A) Distribution of the BrdU (red) or Ki67-positive cells (green) in the dentate gyrus at P4, after 24 h from BrdU injection. A cluster of dividing cells is present at the fimbriodentate junction of the wild-type (white circle, a). A Reln^CTRdel mutant does not have this cluster (a’). Compared with a corresponding region of the wild type (b), abnormal accumulation of the dividing cells are apparent in the subpial surface of Reln^CTRdel (b’). Enlarged images of marked regions (a, a’, b, b’) are shown below. In the mutant, Ki67-positive cells are closely located on top of BrdU-positive cells (a’ and b’). Scale bars, 100 µm. Scale bars in the enlarged images, 25 µm. Nuclei were stained using Hoechst (blue). (B) The number of total BrdU-positive cells is not significantly different (p = 0.8182; boxplot, median ± IQR; whiskers, min and max). (C) The percentage of BrdU/Ki67 double-positive cells was reduced (p = 0.0022; boxplot, median ± IQR; whiskers, min and max). This represents a population of cells that reentered the cell cycle.