Objective To study the role of activated microglia transplantation in recovery of hindlimb locomotor function in rats with spinal cord injury(SCI). Methods A total of 40 female adult Wistar rats were selected and divided into four groups randomly(10 rats in each group).The former two groups were locomotor function observation groups,in which rat model with spinal cord was established by striking with improved self-made Allen's strike equipment to fabricate moderate spinal cord injury and divided into transplantation group and control group.The latter two were histological observation groups,the spinal cord injury model was fabricated by the same above-mentioned method and divided into transplantation and control groups.Before fabricating the spinal cord injury model,the microglia of the newborn rats were cultured,separated,purified and identified and the purity of the microglia determined.The injury position was exposed again seven days after transplantation and the cell suspension of microglia was injected around the injury position with microsyringe,which was free in the control group.The hindlimb locomotor function of rats was detected and scored at 1 day,1,2,3 and 4 weeks in the locomotor function observation groups after transplantation respectively.At the same time,two rats were extracted randomly from the control group and the transplantation group in histological observation groups to cut specimen and slice for Naoumenko-Feign paraffin section and dying.Then,the microglia were observed and counted by microscope and analyzed statistically. Results At 1,2,3 and 4 weeks after operation,the BBB score of the control group and the transplantation group was increased gradually with the time.But compared with the control group,transplantation group had higher scores of hindlimb locomotor function at 2,3 and 4 weeks after operation,with statistical difference(P＜0.05).Naoumenko-Feigin paraffin section and dying and microglia counting showed that positive microglia number in the transplantation group was increased more obviously than the control group,with statistical difference(P＜0.05).Conclusion Activated microglia transplantation can promote the recovery of the hindlimb locomotor function in SCI rats.

Objective To investigate mRNA and protein expressions of TGF-β1 and their signifi-cance in injured spinal cord after transplantation of activated microglia. Methods Wistar rat model of spinal cord injury was made by using modified Allen's method. Then, the activated microglia was trans-planted into spinal cord injury models tu detect mRNA and protein expressions of TGF-β1 in the spinal curd. Results The mRNA and protein expressions of TGF-β1 in control group were significantly lower than that in test group (P<0.05). Conclusion Transplantation of activated microglia to the impaired spinal cord in rats can increase the mRNA and protein expressions of TGF-β1. The up-regulated expres-sion of TGF-β1 in spinal cord may play a role in promoting the recovery of spinal cord, when the activated microglia may be the main saurce of TGF-β1.