Tsering C
Department of Neurology, Henry Ford Hospital, Detroit, Mich. 48022.
Dev Neurosci. 1992;14(4):308-11. doi: 10.1159/000111676.
Unlike the afferent input into the spinal cord, it is generally believed that the motor efferent system in the mammalian spinal cord is more segmental in arrangement. Isolated comments in recent reports suggest that motor neurons in the mammalian spinal cord may be strictly segmental, contrary to many earlier reports using less sophisticated methods. We have attempted to address the question of the segmental arrangement of motor neurons in a mammalian spinal cord using single and double labelling with the fluorescent lipophilic dyes, Di I and Di A. These dyes have the ability to diffuse along and stain the plasma membrane of the neural elements in aldehyde-fixed specimens. Sprague-Dawley rat fetuses and early postnatal pups were used. The study was conducted on the thoracic spinal cord. The results confirm that thoracic spinal motor neurons are restricted to the segments from which their axons exit via the ventral roots in the intrauterine stages of development. The segmental arrangement of motor neurons in the thoracic spinal cord corresponded well with that of the sympathetic preganglionic neurons which were stained simultaneously.
与传入脊髓的输入不同，人们普遍认为哺乳动物脊髓中的运动传出系统在排列上更具节段性。近期报告中的一些孤立评论表明，哺乳动物脊髓中的运动神经元可能严格呈节段性分布，这与许多早期使用不太精密方法的报告相反。我们试图通过使用荧光亲脂性染料Di I和Di A进行单标记和双标记，来解决哺乳动物脊髓中运动神经元节段性排列的问题。这些染料能够沿着醛固定标本中的神经元件的质膜扩散并对其进行染色。使用了斯普拉格-道利大鼠胎儿和出生后早期幼崽。研究在胸段脊髓上进行。结果证实，胸段脊髓运动神经元在子宫内发育阶段局限于其轴突通过腹根穿出的节段。胸段脊髓中运动神经元的节段性排列与同时被染色的交感神经节前神经元的节段性排列非常吻合。
