Changes Of NT-3 Expression In Rat Motocortex And Red Nucleus Following Complete Spinal Cord Transection

Objective: Changes of neurotrophin-3 (NT-3) expression in rat motocortex and red nucleus following complete spinal cord transection have been studied in order to provide the experimental evidences for the mechanisms of regeneration and repair after spinal cord injury and for neurotrophins to treat spinal cord injury. Methods: Male Sprague-Dawley rats weighing 240-260 g were divided into three groups at random:(1)Spinal cord transection group which was randomly subdivided into four subgroups according to the survival time at the day 1,3,7and 14dpostoperative (n=6 for each time point).In this group,the spinal cord of rat was transected completely at thoracic level 10-11.(2)Sham operation group (laminectomy only,n=6).(3)Normal control group (n=6).The expression of NT-3 in motocortex and red nucleus was examined by immunohistochemistry and image analysis. Results: NT-3 immunoreactive cells were found in motocortex layer â…¤and red nucleus in both control and experimental groups.After operation, the expression of NT-3 was increased gradually and reached the peak at the day 3 in motocortex ,as well as at the day 7 in red nucleus.Our data reveal the profile of NT-3 expression in motocortex and red nucleus after complete spinal cord transection at thoracic level. Conclusion: The results suggest that the demand of NT-3 increases in motocortex and red nucleus after spinal cord injury and the increase of endogenous NT-3 may be beneficial for the survival and regeneration of the injured corticospinal and rubrospinal neurons.