Abstract: Objective To explore the restoration of motor function and the expression of calcitonin gene-related peptide(CGRP)and acetylcholine esterase(AChE)in the anterior horn motoneurons after different types of spinal cord injury.Methods 60 adult female Wistar rats were randomly assigned to 3 groups:sham group,completely transection group and contusion group.Average combined scores(ACOS)were applied to assess the motor function at various time after the surgery.The content of AChE in the anterior horn of L₂-L₄ was detected with Karnovsky-Roots staining and the expression of CGRP was then determined with immunohistochemistry.Results The scores of ACOS were much higher in the contusion group than in the transection group at each time point examined.The content of both AChE and CGRP significantly decreased after either type of spinal cord injury.However,their activity gradually recovered to the normal level in the contusion group,but not in the transection group.Moreover,the changes of CGRP occurred earlier than those of AChE.Conclusion There is strong relationship between the motor function recovery and the functional state of anterior horn cells.CGRP or AChE may play an important role in the functional recovery of locomotion after spinal cord injury in rats.

Key words: spinal cord injury(SCI), assessment, motor function, calcitonin gene-related peptide(CGRP), acetylcholine esterase(AChE), rats