Sjöberg J, Kanje M
Department of Zoophysiology, University of Lund, Sweden.
Brain Res. 1990 Oct 8;529(1-2):79-84. doi: 10.1016/0006-8993(90)90812-p.
The aim of this study was to investigate the early period of neurite outgrowth in the regenerating rat sciatic nerve and to determine if the non-neuronal cells were important for the conditioning lesion effect. Regeneration distance was evaluated with the pinch-reflex test 6 h to 5 days after a test crush lesion. The regeneration velocity accelerated during approximately 3 days, whereupon outgrowth continued with a constant velocity. In unconditioned nerves the initial delay was 2.8 h and the constant rate of regeneration was 3.2 mm/day. In nerves with a distal conditioning lesion the initial delay was 2.4 h and the rate of regeneration increased by 52%. When the test crush was applied at the same place as the conditioning crush the initial delay was 1.9 h and the rate of regeneration increased by 61%. The conditioning lesion effect was not influenced by the distance between the cell body and the conditioning crush lesion. Furthermore, the conditioning lesion effect could not be expressed if conditioned axons grew into a freeze injured nerve section. Incorporation of [3H]thymidine increased in the regenerating nerve segment. The increase occurred earlier if this segment had been subjected to a conditioning crush lesion. The results of these experiments showed that peripheral neurites start to regenerate within a few hours after an injury, suggesting that growth cone formation is independent of the cell body reaction. A conditioning crush lesion increases the regeneration velocity and its acceleration, and the conditioning lesion effect cannot be expressed in the absence of living Schwann and other non-neuronal cells.
本研究的目的是调查大鼠坐骨神经再生过程中神经突生长的早期阶段，并确定非神经元细胞对预处理损伤效应是否重要。在试验性挤压损伤后6小时至5天，通过夹捏反射试验评估再生距离。再生速度在大约3天内加速，此后以恒定速度继续生长。在未经预处理的神经中，初始延迟为2.8小时，恒定再生速度为3.2毫米/天。在有远端预处理损伤的神经中，初始延迟为2.4小时，再生速度提高了52%。当试验性挤压与预处理挤压在同一位置进行时，初始延迟为1.9小时，再生速度提高了61%。预处理损伤效应不受细胞体与预处理挤压损伤之间距离的影响。此外，如果预处理的轴突长入冷冻损伤的神经段，则预处理损伤效应无法表现出来。再生神经段中[3H]胸腺嘧啶核苷的掺入增加。如果该段神经受到预处理挤压损伤，增加会更早出现。这些实验结果表明，外周神经突在损伤后数小时内开始再生，这表明生长锥的形成与细胞体反应无关。预处理挤压损伤可提高再生速度及其加速程度，并且在没有活的雪旺细胞和其他非神经元细胞的情况下，预处理损伤效应无法表现出来。
