Hase Takao, Kawaguchi Saburo, Hayashi Hideki, Nishio Takeshi, Mizoguchi Akira, Nakamura Takashi
Department of Integrative Brain Science, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
Eur J Neurosci. 2002 Mar;15(6):969-74. doi: 10.1046/j.1460-9568.2002.01932.x.
The present study aimed to analyse how anatomical regeneration contributes to functional recovery after experimental spinal cord repair. Thoracic spinal cord of neonatal rats was completely transected to make a gap and repaired by grafting a section of embryonic spinal cord. Six weeks after surgery, outcome of locomotor performance was assessed using an open field locomotor scale (BBB scale). Axonal regeneration across the repaired site was quantitatively assessed in the raphe, vestibular, and red nuclei and the sensorimotor cortex by a retrograde tracing method. The rats that had no labelled neurons in any of the supraspinal nuclei showed no hind-forelimb coordination. The rats that had labelled neurons in the brainstem nuclei but not in the sensorimotor cortex showed hind-forelimb coordination of varying grades depending on the amount of regeneration. The rats that had labelled neurons in all of the examined nuclei showed almost normal locomotion. In addition to a relationship between distribution of the labelled neurons and functional recovery, a positive correlation was observed between number of the labelled neurons in each of the supraspinal nuclei and locomotor performance of the rat. Thus the grade of restored function appeared to be regulated by distribution and number of fibres regenerated across the repaired site and into the target region. These results suggest that accurate reconstruction of neural connections is essential for significant functional recovery after spinal cord repair.
本研究旨在分析解剖学上的再生如何促进实验性脊髓修复后的功能恢复。将新生大鼠的胸段脊髓完全横断以制造间隙，然后通过移植一段胚胎脊髓进行修复。术后六周，使用旷场运动量表（BBB量表）评估运动性能结果。通过逆行追踪法对中缝核、前庭核、红核和感觉运动皮层中穿过修复部位的轴突再生进行定量评估。在任何脊髓上核中均无标记神经元的大鼠未表现出后肢与前肢的协调。在脑干核中有标记神经元但在感觉运动皮层中没有标记神经元的大鼠，根据再生量表现出不同程度的后肢与前肢协调。在所有检查核中均有标记神经元的大鼠表现出几乎正常的运动。除了标记神经元的分布与功能恢复之间的关系外，还观察到每个脊髓上核中标记神经元的数量与大鼠的运动性能之间呈正相关。因此，恢复功能的程度似乎受穿过修复部位并进入目标区域的再生纤维的分布和数量调节。这些结果表明，神经连接的精确重建对于脊髓修复后显著的功能恢复至关重要。
