Abstract: Objective To study the effect of traumatic brain injury on the expression of glial cell line-derived neurotrophic factor(GDNF)and its receptors in hippocampus of rats.Methods Male Sprague-Dawley rats were divided into normal control,sham group and injury groups.The rats of injury groups were subjected to Marmarou's closed traumatic brain injury and then were subdivided into 1 h,2 h,4 h,8 h,12 h,24 h,48 h,72 h and 5 d groups according to the time elapsed after injury.The expression of GDNF and its receptors were measured with immunohistochemistry.Results Mild expression of GDNF and its receptors were observed in hippocampus of rats in control group.The number of GDNF positive neurons reached the peak level in hippocampus 2 h after injury,and that of GFRα-1 and Ret positive neurons reached the peak level 4 h after injury.Conclusion The expression of GDNF and its receptors were increased significantly at the early time in hippocampus of rats after injury in a similar temporal patterns after brain injury.

Key words: traumatic brain injury, glial cell line-derived neurotrophic factor, receptor, hippocampus, rats