Abstract: After the model of experimental brain contusion was set up,the changes of GFAP,PCNA were studied by immunohistochemistry SP method combined with image quantity analysis.After contusion,the gray degrees and areas of GFAP-positive cells increased significantly at the 3rd hour,reached the highest level in the 4th day and kept until the 7th day.PCNA-positive cells appeared in the 12th hour, simultaneously, their gray degrees tended to increase and positive areas tended to decrease. It showed regular changes of GFAP,PCNA with various survival times, and these changes were useful in the diagnosis of brain contusion especially in the period from the second to 7th day after injury.The numbers of astrocytes increased and reached the highest level in the 3rd day after contusion while the reactive proliferation of astrocytes is only a minor phenomenon.

Key words: brain contusion, immunohistochemistry, Glial fibrillary acidic protein