Abstract: Objective To observe the changes of cystathionine β-synthase （CBS） expression in the cerebral cortex after brain contusion at different times. Methods An experimental model of traumatic brain injury （TBI） in mice was established by an improved weight-drop device. Then Western blotting and immunohistochemical examination were used to detect the CBS expression in cerebral cortex around injury at different time points （1 h, 6 h, 12 h, 1 d, 2 d, 3 d, 7 d）. Results The results of Western blotting revealed that the expression level of CBS was down-regulated and reached its lowest level at the 3rd days after injury, and then restored to normal level after 7 days. The results of immunohistochemistry showed that CBS was present in the normal brain cortex. CBS expression gradually decreased at the 3rd days after injury, and then restored to normal level after 7 days. Conclusion CBS has the potential to be a reference index for time estimation after brain contusion in forensic practice.

Key words: forensic pathology, brain injuries, cystathionine beta-synthase, injury time, mice