Varejão Artur S P, Cabrita António M, Meek Marcel F, Bulas-Cruz José, Melo-Pinto Pedro, Raimondo Stefania, Geuna Stefano, Giacobini-Robecchi Maria G
Department of Veterinary Sciences, CETAV, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal.
J Neurotrauma. 2004 Nov;21(11):1652-70. doi: 10.1089/neu.2004.21.1652.
Peripheral nerve researchers frequently use the rat sciatic nerve crush as a model for axonotmesis. Unfortunately, studies from various research groups report results from different crush techniques and by using a variety of evaluation tools, making comparisons between studies difficult. The purpose of this investigation was to determine the sequence of functional and morphologic changes after an acute sciatic nerve crush injury with a non-serrated clamp, giving a final standardized pressure of p = 9 MPa. Functional recovery was evaluated using the sciatic functional index (SFI), the extensor postural thrust (EPT) and the withdrawal reflex latency (WRL), before injury, and then at weekly intervals until week 8 postoperatively. The rats were also evaluated preoperatively and at weeks 2, 4, and 8 by ankle kinematics, toe out angle (TOA), and gait-stance duration. In addition, the motor nerve conduction velocity (MNCV) and the gastrocnemius-soleus weight parameters were measured just before euthanasia. Finally, structural, ultrastructural and histomorphometric analyses were carried out on regenerated nerve fibers. At 8 weeks after the crush injury, a full functional recovery was predicted by SFI, EPT, TOA, and gait-stance duration, while all the other parameters were still recovering their original values. On the other hand, only two of the histomorphometric parameters of regenerated nerve fibers, namely myelin thickness/axon diameter ratio and fiber/axon diameter ratio, returned to normal values while all other parameters were significantly different from normal values. The employment of traditional methods of functional evaluation in conjunction with the modern techniques of computerized analysis of gait and histomorphometric analysis should thus be recommended for an overall assessment of recovery in the rat sciatic nerve crush model.
周围神经研究人员经常使用大鼠坐骨神经挤压模型来研究轴突断裂。不幸的是，不同研究小组的研究报告了不同挤压技术的结果，并且使用了各种评估工具，这使得不同研究之间难以进行比较。本研究的目的是确定使用非锯齿状夹钳对坐骨神经进行急性挤压损伤后（最终标准化压力为p = 9 MPa）功能和形态学变化的顺序。在损伤前以及术后每周直至第8周，使用坐骨神经功能指数（SFI）、伸肌姿势推力（EPT）和退缩反射潜伏期（WRL）评估功能恢复情况。还在术前以及术后第2、4和8周通过踝关节运动学、外展角（TOA）和步态站立持续时间对大鼠进行评估。此外，在安乐死前不久测量运动神经传导速度（MNCV）和腓肠肌 - 比目鱼肌重量参数。最后，对再生神经纤维进行结构、超微结构和组织形态计量学分析。挤压损伤后8周，SFI、EPT、TOA和步态站立持续时间预测功能完全恢复，而所有其他参数仍在恢复到原始值。另一方面，再生神经纤维的组织形态计量学参数中只有两个，即髓鞘厚度/轴突直径比和纤维/轴突直径比恢复到正常值，而所有其他参数与正常值有显著差异。因此，建议采用传统功能评估方法与步态计算机分析和组织形态计量学分析等现代技术相结合，以全面评估大鼠坐骨神经挤压模型的恢复情况。
