功能训练促进颈脊髓损伤大鼠功能恢复的机制研究

目的：探讨大鼠颈脊髓不完全性损伤后前肢功能训练促进大鼠前肢功能恢复的机制.方法：在立体定位仪的引导下,致伤大鼠双侧红核和皮质脊髓背侧束后,对大鼠行前肢功能训练6周.免疫组化检测损伤脊髓节段脑源性神经生长因子（brain-derived neurotrophic factor,BDNF）的表达,皮质脊髓束投射神经元（corticospinal neurons,CSNs）中生长相关蛋白43（growth-associated protein 43,CAP43）和神经营养素共同受体P75（P75NTR）的表达,荧光金逆行示踪CSNs存活情况.结果：大鼠不完全性颈脊髓损伤后,前肢功能训练可上调脊髓前角神经元BDNF与CSNs中GAP43和P75NTR的表达,减少CSNs死亡.结论：大鼠颈脊髓不完全性损伤后,前肢功能训练通过上调脊髓前角神经元BDNF与CSNs中GAP43和P75NTR的表达以及减少CSNs的死亡等机制增加未损伤皮质脊髓腹侧束（vCST）的出芽,进而促进大鼠前肢功能恢复.

Mechanisms of functional recovery due to forelimb training after cervical spinal cord injury in rats

Objective:To explore the possible mechanisms of functional recovery due to forelimb training after incomplete cervical spinal cord injury(iCSCI) in rats.Method:Under the guide of Stereotaxical,the red nuclei and cervical dorsal corticospinal tract(dCST) were injured,and then the rats accepted forelimb training for consecutive 6 weeks.The expression of brain-derived neurotrophic factor(BDNF) in the injured spinal cord was monitored by fluorescent immunohistochemistry,and the expression of growth-associated protein(GAP43) and P75NTR in corticospinal neurons(CSNs) was examined by immunohistochemistry.Also,the survival status of CSNs was visualized by Fluord-Gold labeling.Result:Forelimb training promoted functional recovery of forelimb.It could aslo enhance the sprouting of ventral uninjured corticospinal tract(vCST),and up-regulate the expression of GAP43 and P75NTR in CSNs and the expression of BDNF in spinal neuron of anterior horn.Also and reduce the death of CSNs.Conclusion:After iCSCI in rats,forelimb training can up-regulate the expression of BDNF in spinal cord and the expression of GAP43 and P75NTR in CNSs,and reduce the death of CSNs.These changes lead to the enhancing sprouting of uninjured vCST,which results in forelimb function recovery.