移植大鼠脊神经前后根重建脊髓白质纤维束的形态学

A morphological study on the reconstruction of the white matter fasciculi of the spinal cord with transplanted anterior and posterior spinal nerve roots in rat

目的:观察移植脊神经前后根重建脊髓白质纤维束的形态学情况。方法:取4周龄SD大鼠,分为移植组、损伤组和假手术组。移植组损伤第10~12胸段脊髓,然后切取脊髓损伤区废用的脊神经前根和后根,并将前根移植到脊髓损伤区域的皮质脊髓束位置,再将后根移植到薄束位置,脊髓与移植的神经根进行显微吻合,同时切取第12、13肋间神经连接损伤节段上下的脊神经,留置导管给予胶质细胞源性神经营养因子(GDNF)、轴突生长相关蛋白(GAP-43)、突触分化诱导基因产物1(SynDIG1)。损伤组仅损伤第10~12胸段脊髓。假手术组仅切开皮肤和分离肌肉,不损伤脊髓。术后7、30、60、90 d,行斜板实验、BBB功能运动评分、神经电生理检测方法检测3组大鼠运动功能。免疫荧光染色显示移植区脊髓组织吻合段神经组织结构变化及神经细胞的活性。结果:肉眼观察损伤组脊髓组织缺损、断端出现萎缩现象,移植组脊髓吻合段组织光滑圆润,没有明显萎缩现象,吻合段在显微镜下可见神经纤维排列整齐、走行一致。移植组斜板实验、BBB功能运动评分明显高于损伤组,体感电位、运动诱发电位潜峰时较损伤组明显缩短。结论:移植脊神经前后根重建脊髓白质纤维束,神经组织结构吻合修复良好,有利于神经信号传递,促进下肢运动功能的恢复。

Objective:To observe the morphological changes of the white matter fascicului of the reconstituted spinal cord after the transplantation of anterior and posterior spinal nerve root.Methods:Four-week-old SD rats were divided into a transplantation group,an injury group,and a sham-operation group.In the transplantation group,the disuse anterior and posterior roots of the spinal cord were harvested after the injury of the 12th and 13th thoracic cord.The anterior roots were transplanted to the corticospinal tract of the injured cord and the posterior roots were transplanted to the fasciculus gracilis by microsurgery.The 12th and 13th intercostal nerves were excised.GDNF,GAP-43,and SYNDIG1 were given with indwelling catheter.The 12th and 13th segment of thoracic cord was only damaged in the injury group,but no other treatment was done.In the sham-operation group,only the skin was cut to separate the muscle without damaging the spinal cord.After 7,30,60 days and 90 days,the motor function of the lower limbs was measured by tilta table test,a BBB functional motor score,and an electrophysiological test.The experimental animals were killed,and the spinal cord of the transplanted area was taken out.The structural changes of nerve tissue and the activity of nerve cells were shown by immunofluorescence staining.Results:The defect of spinal cord and the atrophy of broken end were observed by naked eye in the injured group.In the transplantation group,the anastomotic tissue was smooth and round,and there was no obvious atrophy.The tilt table test and BBB motor function score in the transplantation group were significantly higher than those in the injury group,and the latent peaks of somatosensory and motor evoked potentials were significantly shorter than those in the injury group.Conclusion:The anterior and posterior roots of spinal nerves are transplanted to reconstruct the fasciculi of white matter in spinal cord,and the nerve tissue structure is anastomosed and repaired well,which is conducive to nerve signal transmission and promote the recovery of lower limb motor function.