Abstract: Objective To study effects of embryonic neural stem cells on trauma of red nucleus neurons of the rats with spinal cord injury after transplantion. Methods NSCs in logarithmic phage were labeled with Brdu，a Sprague Dawley rat mode of spinal cord injury(SCI) was induced with electrocircuit control spinal cord injuring device. 30 SD rats were randomly divided into three groups: sham group，SCI group, NSC group. The NSCs were transplanted into the injured site three days after SCI. Then NSCs labeled with Brdu were detected by immunohistochemisty, rubrospinal tract (RST) neurons were labeled by retrograde transport of the horseradish peroxidase (HRP) from the lesion site, which were taken by damaged axons and remained in the neurons, then the labeled red nucleus (RN) neurons were counted. Hind limb function of experimental rats was evaluated by a blinder observer using BBB open field locomotion rating score. Results NSCs can be detected in the spinal cord after transplantation. the number of RST neurons labeled by HRP in NSC group was more than that in SCI group (P<0.01), the BBB score of NSC group were higher than SCI group (P<0.01).Conclusions The transplanted NSCs can survive in the injured site of spinal cord and protect RN, then promote more remarkably functional recovery after SCI.

Key words: SCI, NSCs, RN