Abstract: Objective To observe changes of BDNF expression in hippocampus and spinal cord of rats after compression-induced spinal cord injury. Methods The CSCI model was established with a self-made device. BDNF in astrocyte, neuron, antegrade and retrograde axons were detected by immunofluorescence. The expression changes of BDNF in hippocampus, lesion centre, the superior segment and the inferior segment which were adjacent to the lesion centre were also determined by western blotting methods. Results The fluorescence intensity of BDNF+-GFAP in lesion centre were increased, while BDNF+-Tuj1 was decreased with time going after CSCI. BDNF+-NF200 in superior and inferior segment of lesion were increased. The expressions of BDNF in hippocampus, the superior segment and the inferior segment close to the lesion centre reached its peak on the 1st day and then were decreased with the duration of time after CSCI(P<0.05). The expression of BDNF in lesion centre was decreased gradually(P<0.05). Conclusion: Decreasing level of BDNF is regular and may lead to neuronal reduction with compressing time going.

Key words: compression-induced spinal cord injury, brain derived neurotrophic factors, neuron, astrocyte