Abstract: Objective To investigate the retrograde amnesia changes within different injury levels of cerebral concussion in rats. Methods A metallic pendulum striker device of brain injury was deployed to duplicate CC models of different injury levels within Stragu-Dawley(S-D) rats. The investigated animals were divided into two groups according to classification standard, that is, Pure Cerebral Concussion (PCC) group and Complicated Cerebral Concussion (CCC) group. One control group was used ,and each group included 8 animals. The retrograde amnesia of each group was assessed by Morris Water Maze (MWM) Test from 3 days preinjury to 7 days postconcussion. Results Compared with the control group, the retrograde amnesia was detected within 3 days in PCC group, and 5 days in CCC group after injury. At the same time, the two groups both manifested space recognition deficit. Conclusion The retrograde amnesia existed in both pure cerebral concussion group and complicated cerebral concussion. Furthermore, the lasting time of retrograde amnesia in animals correlates to the injury level of brain concussion.

Key words: rat, cerebral concussion, injury level, retrograde amnesia, morris water maze