FIGURE 2.

Representative images of immunohistological staining (brown) of OMP-positive (OMP⁺) cells (A), SOX2⁺ ORN progenitor cells (B), GAP43⁺ immature ORNs (C), Ki67⁺ proliferating cells (D), and cleaved Cas3⁺ apoptotic cells (E). Each cell except for many OMP⁺ cells is indicated by arrows. Tissue sections were counterstained with the nuclear dye hematoxylin (blue). Numbers of SOX2⁺ ORN progenitors and Ki67⁺ actively proliferating cells per mm of the basal layer and OMP⁺ mature ORNs, GAP43⁺ immature ORNs, and Cas3⁺ apoptotic cells per mm of the OE in saline or rhIGF-1-treated mice. Open circles, rectangles, and triangles represent the values for each mouse in the saline, low-IGF-1, and high-IGF-1 treated groups (each n = 6), respectively. The horizontal lines represent the mean value for each group. ^∗P < 0.05; ^∗∗P < 0.01; ^∗∗∗P < 0.001; and ^∗∗∗∗P < 0.0001 (one-way ANOVA).