目的:观察利用脊神经前根吻合重建脊髓损伤大鼠股四头肌神经反射通路的形态学情况。方法:取4周龄SD大鼠20只,体重120~150g;将左侧L1神经前根与支配股四头肌的优势脊神经(L3)前根通过尾神经桥接吻合,右侧不作任何处理。神经吻合术后6个月,手术分离神经吻合段。将能分离神经吻合段的大鼠在L2脊髓水平左半侧切断脊髓制备大鼠脊髓半切损伤模型,饲养4周后左侧股神经注射Trueblue(TB)染色剂进行逆行荧光染色,观察L1脊髓前角是否有TB标记的阳性细胞;同时解剖分离神经吻合段进行HE染色及电镜观察。结果:饲养过程中大鼠死亡4只。成功分离出10只大鼠的神经吻合段。吻合段神经肉眼观察光滑圆润,无萎缩;HE染色光镜下吻合段神经纤维排列整齐,走行一致,为典型的有髓神经纤维结构;电镜下吻合段神经纤维具有明显神经轴突特征。TB荧光逆行示踪左侧L1脊髓前角可见荧光标记阳性的神经元,而右侧无标记阳性细胞。结论:L1与L3脊神经前根吻合可成功建立L2脊髓半切损伤大鼠的股四头肌脊髓旁神经反射通路。
Objective:To observe the neural morphology after reconsruction of nervous reflex pathway of quadriceps femoris through spinal ventral root anastomoses after spinal cord injury in rats.Method:Twenty 4-week-old SD rats of 120g to 150g were collected.The left L1 ventral root and L3 ventral root,which mainly dominate quadriceps femoris,were anastomosed end-to-end by coccygeal nerve,while the right side was kept intact.6 months later,neural anastomosis was extracted from experimental rats.The spinal cord at the L2 level was hemitransected to establish the hemitransection model in experimental rats,which could be successfully dissceted.After 4 weeks of breeding,Trueblue(TB) fluorescence reagent was injected into the left femoral nerve and the TB fluorescence marked neural cells was observed in L1 ventral horn.The nerve anastomosis was stained by Hematoxylin and Eosin(HE) staining kit and observed through electronic microscopic.Result:Four rats deseased during breeding,and the neural anastomosis could be successfully extracted from the 10 experimental rats.The neural anastomosis showed round,smooth and non-atrophic under naked eye.Under microscope the new regenerating neural fiber of anastomosis lined in sequence and uniformity by HE staining,which was the classic medullated nerve fibers.The anastomoses fiber presented with the characteristic of common neural axon.The TB fluorescence marked neural cells appeared on the left side of L1 ventral horn and something like somatic motor nerve cell morphologically,while no TB marked cell appeared on the right side.Conclusion:New paraspinal pathway of quadriceps femoris can be established by L1-L3 spinal ventral roots anastomosis after spinal cord injury at L2 level hemitransection in rats.