Effect of rhEPO on BrdU-positive cells in the hippocampus 35 days after TBI. TBI alone significantly increases the number of BrdU-positive cells in the ipsilateral DG, CA3 and CA1. The cells with BrdU (brown stained) that clearly localize to the nucleus (hematoxylin stained) are counted as BrdU-positive cells (arrows in D and F). However, delayed treatment with rhEPO (E, F) does not show significant effects on cell proliferation as compared with the saline group (C, D). Scale bar = 50μm (A, C, E); 25μm (B, D, F). The number of BrdU-positive cells is shown in (G). Data represent mean ± SD. *p < 0.05 vs. corresponding Contralateral. N (mice/group) = 12 (EPO); 13 (Saline); 8 (Sham).