Abstract: Objective To investigate Homer protein expression after focal brain contusion and explore the relationship between expression and injury time. Methods Focal brain contusion in rats was established and Homer protein expression in brain at different injury intervals after contusion was detected by immunohistochemistry and Western blotting. Results A small amount of Homer positive expression cells were detected in control group, sham operated group and experimental group （0.5 h after contusion）. The amount of Homer positive expression cells increased after 3 h and reached peak 12 h after contusion. The amount of positive cells continued to decrease 1 d after contusion and to the base level 7 d after contusion. Homer protein expression based on immunohistochemistry and Western blotting had statistical difference among adjacent groups. Conclusion Expression of Homer protein near the focal contusion area shows time dependence after brain contusion in rats.

Key words: forensic pathology, brain injuries, blotting, Western, immunohistochemistry, Homer protein, rats