关键词: 液压冲击脑损伤, BDNF, TrKB, 免疫组织化学, 图像分析

Abstract: Objective Study on the pattern of changes of BDNF and it's receptor TrKB occurred in the experimental brain injury model for further ascertaining the molecular mechanism of brain injury. Methods Three groups were settled, including: normal control, operation sham control and experimental group. Moderate severity of brain injury (0.2MPa) was established by the fluid percussion method. In the later case, 10 subgroups were divided,: 5 rats each group. Immunohistochemistry ABC method was used for studying the immuno-reactivity of both BDNF and TrkB factors. Results Unilateral FP brain injury induced a bilateral increasing in levels of both BDNF and TrK B factors.The immuno-reactivity of both BDNF and TrKB factors increased in granule and pyramidal layers in cortex, CA3 regions of hippocampus as well as the Purkinje neurons of cerebellum 1h after brain injury, reached to the peak at 3-6h, remained above normal level up to 12h and then declined to normal control level at 24h after brain injury. Significant difference in gene expression of both BDNF and TrkB were found between the 1h, 3h, 6h and 12h subgroups of experimental groups and both normal and operation sham control groups. Conclusion The results demonstrated that the brain injury induced the gene expressions not only the IEGs, but also both BDNF and it's receptor TrKB. The pattern of BDNF and TrKB level changes were quite regular which might be used for timing of injury in forensic medicine aspect. The role of these two factors in molecular mechanism of brain injury has been discussed.

Key words: Fluid percussion brain injury, BDNF, TrKB, immunohistochemistry, image analysis system