Effects of exercise on pCREB in adult and D-gal treated mice. Immunohistochemistry for phosphorylated cAMP-response element binding protein (pCREB) in the dentate gyrus the S-Veh (A), Ex-Veh (B), S-D-gal (C), and Ex-D-gal (D) groups. Granule cell layer, GCL; polymorphic layer, PoL; ML, molecular layer. Bar =50 μm. E: Mean number of pCREB-positive nuclei per section in all groups ( aP <0.05, between vehicle vs. D-gal groups, bP <0.05, between sedentary vs. exercise groups). All data are shown as the mean ± SEM.