Abstract: Objective To study the effect of neural stem cell transplantation on neurological behavior and expressions of Caspase-3 and Caspase-9 in rats with traumatic brain injury (TBI). Methods A total of 108 SD rats were randomly divided into the sham group (n=36), traumatic brain injury group (TBI, n=36) and neural stem cell transplantation group (NSC, n=36). TBI model of rats was established by using improved Feeney method. Rats of NSC group were injected neural stem cells in cortex after traumatic brain injury was established for 1 week, and then nurological severity scores (NSS) of rats were evaluated at 7 days, 14 days and 21 days after cell transplantation in TBI and NSC groups, respectively. Rats of sham group were only cut the scalp and exposed the skull without striking. The expressions of Caspase-3 and Caspase-9 in brain tissues were detected by immunohistochemistry and Western blot method. Results Compared with NSC group at the same time points, NSS was decreased significantly in TBI group (P<0.01). Compared with the sham group, the optical density (OD) values of Caspase-3 and Caspase-9 positive expressions were increased significantly in TBI group (P<0.05). Compared with TBI group at the same time points, the OD values of Caspase- 3 and Caspase- 9 positive expressions were decreased significantly in NSC group (P<0.05). Conclusion The neural stem cell transplantation can promote the recovery of brain injury by down-regulating the expressions of Caspase-3 and Caspase-9.

Key words: brain injuries, stem cell transplantation, neurons；caspase 3, caspase 9, disease models, animal