The proliferation and migration of endogenous neural stem cells in cerebral tissue of newborn rat with hypoxic-ischemic brain damage

Objective To investigate the proliferation and migration of endogenous neural stem cells after hypoxic-ischemic brain injury (HIBD) in newborn rats. Methods The HIBD model was induced in 30 newborn rats by ligation of left common carotid artery followed by 8% O 2 2.5 hours. Bromodeoxyuridine (BrdU, 50 μg/g, tid for 3 days) were intraperitoneally administered to the newborn rats in injured group and control group. Rats were sacrificed at different given time points and brains were then harvested. The dynamic expressions of BrdU and Nestin were visualized by immunocytochemical staining. Results In the normal newborn rats, the BrdU positive cells in the brains reached a maximum at postnatal 3 days, and then decreased gradually. After HIBD, the BrdU positive cells in the brains were significantly increased. The positive cells mainly located at subventricular zone, even though some solitary positive cells could be noted in cortex, striatum and hippocampus. Twenty-one days later, the maximum amount of positive cells were noted in the injured areas. The patterns of staining for Nestin were similar to those for BrdU staining. Conclusion Our results indicate that HIBD stimulates the proliferation and migration of endogenous neural stem cells in the brains of newborn rats.