大鼠三角肌前,后部的运动神经元

为了解主动肌与拮抗肌的运动神经元，应用ＨＲＰ逆行追踪技术研究了大鼠三角肌前部、后部的运动神经元。三角肌前部的运动神经元池位于Ｃ４－６脊髓前外侧核背部及其与后外侧核之间。三角肌后部的运动神经元池位于Ｃ４－７脊髓外侧核及其与前外侧核之间。与前池略有重叠。

MOTONEURONS INNERVATING ANTERION AND POSTERIOR PARTS OF DELTOID MUSCLE IN RAT

Motoneurons innervating anterior and posterior parts of rat deltoid muscle were labeled with retrograde transport of horseradish peroxidase to research into motoneurons of angonist and antagonist muscles. The pool of motoneurons innervating anterior part of deltoid muscle in rat was located in vantrolateral nuclei and the area between ventrolateral nuclei and dorsolateral nuclei in spi-nal segment of C4 ~ C6, and the pool of motoneurons of posterior part was located in dorsolateral nuclei and the area between dorsolateral nuclei and ventrolateral nuclei in spinal segment of C4 ~ C7. The two pools overlapped in the neighbouring area. The length of the pool and the number of labeled soma in the latter pool was about three times as great as that in the former pool. The percentage of labeled soma with mean diameters above 25pm in the latter pool was smaller than that in the former pool and there were similar differences between the two pools in the number and total diameter of first-order dendrites originating from the soma.