Migration of neural stem cells to ischemic brain regions in ischemic stroke in rats

An established rat model of ischemic stroke, produced by temporary middle cerebral artery occlusion and reperfusion (MCAO/R), was used in the evaluation of organ migration of intra-arterial (IA) transplantation of neural stem cells (NSCs). Immediately after transplantation, ischemic rats (n=8) transplanted with either NSCs (MCAO/R+NSC group) or NSC growth medium (MCAO/R+medium group) exhibited neurological dysfunction but rats in a sham+NSCs group (n=5) did not. During the post-operative period, neurological function improved to a similar extent in both MCAO/R groups. At 10 and 14 days post-transplantation, neurological function in the MCAO/R+NSC group was superior to that in the MCAO/R+medium group (p<0.001). Hematoxylin-eosin staining showed neuronal degeneration and necrosis in ischemic rats. Immunofluorescence staining revealed that NSCs had migrated to the frontal and parietal lobes, caudate, and putamen. Some cells had begun differentiating into neurons and astrocytes. Rat NSCs can migrate into the ischemic region, survive, and differentiate into astrocytes and neurons, and thereby potentially improve neurologic function after cerebral ischemia.