Effect of aging on neuroblast migration. (A) Scheme, (B) representative images, and (C, D) number of neuroblasts (doublecortin+ DCX+ cells) in three migratory zones (Z1, Z2, Z3) at 7 and 14 days after MCAO in young and aged mice. Migratory zones were established from the SVZ (Z1) through the corpus callosum (Z2) toward the damaged area (Z3) (see Methods). Data are mean ± SD, n = 6 to 8, *P < 0.05. Scale bar = 200 μm. MCAO, middle cerebral artery occlusion.