Lago Natalia, Rodríguez Francisco J, Guzmán Mónica S, Jaramillo Jéssica, Navarro Xavier
Group of Neuroplasticity and Regeneration, Department of Cell Biology, Physiology and Immunology, and Institute of Neuroscience, Universitat Autònoma de Barcelona, Bellaterra, Spain.
J Neurosci Res. 2007 Sep;85(12):2800-12. doi: 10.1002/jnr.21286.
Nerve regeneration after complete transection does not allow for adequate functional recovery mainly because of lack of selectivity of target reinnervation. We assessed if transplanting a nerve segment from either motor or sensory origin may improve specifically the accuracy of sensory and motor reinnervation. For this purpose, the rat sciatic nerve was transected and repaired with a silicone guide containing a predegenerated segment of ventral root (VR) or dorsal root (DR), compared to a silicone guide filled with saline. Nerve regeneration and reinnervation was assessed during 3 months by electrophysiologic and functional tests, and by nerve morphology and immunohistochemistry against choline acetyltransferase (ChAT) for labeling motor axons. Functional tests showed that reinnervation was successful in all the rats. However, the two groups with a root allotransplant reached higher degrees of reinnervation in comparison with the control group. Group VR showed the highest reinnervation of muscle targets, whereas Group DR had higher levels of sensory reinnervation than VR and saline groups. The total number of regenerated myelinated fibers was similar in the three groups, but the number of ChAT+ fibers was slightly lower in the VR group in comparison with DR and saline groups. These results indicate that a predegenerated root nerve allotransplant enhances axonal regeneration, leading to faster and higher levels of functional recovery. Although there is not clear preferential reinnervation, regeneration of motor axons is promoted at early times by a motor graft, whereas reinnervation of sensory pathways is increased by a sensory graft.
完全横断后的神经再生无法实现充分的功能恢复，主要原因是靶神经再支配缺乏选择性。我们评估了移植运动或感觉来源的神经节段是否能特异性提高感觉和运动再支配的准确性。为此，将大鼠坐骨神经横断，并用含有预变性腹根（VR）或背根（DR）节段的硅胶导管进行修复，与填充生理盐水的硅胶导管作比较。在3个月期间，通过电生理和功能测试、神经形态学以及针对胆碱乙酰转移酶（ChAT）的免疫组织化学染色来标记运动轴突，对神经再生和再支配情况进行评估。功能测试表明，所有大鼠的再支配均成功。然而，与对照组相比，两个接受根异体移植的组达到了更高程度的再支配。VR组显示出对肌肉靶标的最高再支配，而DR组的感觉再支配水平高于VR组和生理盐水组。三组再生有髓纤维的总数相似，但与DR组和生理盐水组相比，VR组中ChAT+纤维的数量略少。这些结果表明，预变性根神经异体移植可增强轴突再生，从而实现更快且更高水平的功能恢复。尽管没有明确的优先再支配情况，但运动移植在早期促进运动轴突的再生，而感觉移植则增加感觉通路的再支配。
