Study on the Time Phases of GAP-43 Expression Following Spinal Cord Injury
Zhang Qinan Li Juncen Ding Peipei Zhang Xiao1 (Department of Experimental techonogy,Chengdu Medical College,Chengdu 610081,China)2 (Grade 2006 of Testing Faculty,Chengdu Medical College,Chengdu,610081,China)
Objective To investigate changes of the expression of growth associated protein (GAP-43) in adult rats with spinal cord injury in different period,and to explore its significance in spinal cord recovery. Methods Each rat were received a contusion on its spinal cord at T10 with a modified Allen's impactor. Following 1,3,5,7 and 14 days,the spinal cord of the rats were taken to conduct immunohistochemical staining for GAP-43. GAP-43 positive cells were counted and the integrated optical density (IOD) was also monitored. Results The experssion of GAP-43 was shown to be in cytoplasm and processes of neurons,which being more significant in the former horn motor neurons. The immunohistochemical response gradully increased within the first 1 week after injury,with the IOD value reaches peak in the 5th day (P0.05),and decreased obviously in the next week (P0.05). Conclusion Spinal cord injury may induce transient up-regulation of the expression of GAP-43 in the area adjacent to injured site,and the experssion of GAP-43 being the peak in about one week after injury,indicating that GAP-43 may participate in the recovery of spinal cord after injury.