Abstract: Objective To investigate the neuroprotective effect of granulocyte colony stimulating factor (G-CSF) combined with behavior training on the learning and memory abilities of cerebral ischemic injury in rats. Methods 96 Wistar rats, 2 months old, were divided as sham group (group A), model group (group B), G-CSF group (group C) and G-CSF+training group (group D). Modified middle cerebral artery occlusion (MCAO) was used to establish a ischemia 2 h/reperfusion 24 h model to all the rats, except sham group. 6 rats were selected in each group 1, 2, 4 and 8 weeks after successfully modeled, respectively. The abilities of learning and memory were detected with the latency of shuttle test video analysis system. The pathology of the hippocampus and the expression of nerve growth factor (NGF) and G-CSF were observed with HE and immunohistochemistry staining, respectively. Results The expression of NGF and G-CSF increased in group B transiently, and increased more and longer in the group C and D, especially in group D, as the time passed (P<0.05). The latency of shuttle test increased in group B, C and D, and gently decreased as the time passed, and the decrease more to less were group D, C and B (P<0.05).Conclusion The neuroprotective effects of G-CSF combined with behavior training are strengthened and long term beneficial than G-CSF alone.

Key words: ischemic brain injury, granulocyte colony stimulating factor, behavior training, early intervention