Abstract: Objective To investigate the change of brain lipid binding protein(BLBP) expression in hippocampus dentate gyrus(DG) at different time points after traumatic brain injury (TBI). Methods Seventy-two rats were divided into the injured group, sham group and control group randomly, and then were subjected to a lateral fluid percussion injury (FPI). Western blotting was used to detect BLBP expression. Brains were sectioned for immunofluorescence staining of BLBP and Vimentin at the time points of 1, 3, 7, 14 days after TBI.Results The results of Western blotting showed that the BLBP expression was lower than that of control group at 1 day post injury（EM>P/EM><0.01） and reached the peak compared with the other groups at 7 days after injury（EM>P/EM><0.01）, then descended at 14 days compared with control group after injury（EM>P/EM><0.01）. The changes of BLBP and Vimentin double-label positive cells were consistent with the results of Western blotting. The BLBP and Vimentin double-label positive cells were found mainly at the subgranular zone of ipsilateral injured hippocampus DG, and most of them were radial glia like cells; BLBP and Vimentin double-labelled positive cells were found at the hilus of DG at 7days after injury, and most of them looked like reactive astrocytes. Conclusion The expression of BLBP in DG after TBI decreased firstly, then increased and reached peak at 7 days after injury, decreased dramatically again at last. The

Key words: Traumatic brain injury, Dentate gyrus, Radial glia cell, Brain lipid binding protein, Vimentin, Western blotting, Immunofluorescence, Rat