Accuracy of reinnervation of rat internal intercostal muscles by their own segmental nerves
Accuracy of reinnervation of rat internal intercostal muscles by their own segmental nerves
复制标题
大鼠肋间内肌自身节段神经重新神经支配的准确性
作者：
V. J. Hardman;M. C. Brown
在肋间肌由其原始神经重新支配后，研究了内部肋间运动神经元在其运动池中的位置。 10 日龄和成年大鼠近端神经切断后 6 至 9 周，在重新神经支配的内肋间肌远端注射 0.1 微升麦芽凝集素 (WGA)-HRP。对侧控制肌肉的相应区域也被注射。逆行标记的运动神经元的位置被绘制在胸脊髓的100微米横截面中，该横截面已经根据Mesulam (1982)的方法进行了HRP染色。在正常大鼠中，支配远端肌纤维的运动神经元主要存在于内部肋间运动神经元库的较背侧部分（Hardman 和 Brown，1985）。在成年大鼠中，再生的运动轴突没有表现出任何选择性；远端肌纤维由运动神经元支配，运动神经元的细胞体分布在整个内部肋间池中。然而，在10天龄手术的大鼠中，远端肋间肌纤维由主要分布在运动池背部的运动神经元重新支配。这些结果支持这样的观点：位置信号对于组织发育过程中肌肉内轴突末端的分布可能很重要。
The positions of internal intercostal motoneurons within their motor pool were studied, following reinnervation of the intercostal muscles by their original nerves. Six to 9 weeks after proximal nerve section in 10-d-old and adult rats, 0.1 microliter injections of wheat germ agglutinin (WGA)-HRP were made in the distal part of the reinnervated internal intercostal muscle. The corresponding region of the contralateral control muscle was also injected. The positions of the retrogradely labeled motoneurons were mapped in 100 microns transverse sections of thoracic spinal cord that had been stained for HRP according to the method of Mesulam (1982). In normal rats, motoneurons innervating distal muscle fibers are found largely in the more dorsal part of the internal intercostal motoneuron pool (Hardman and Brown, 1985). In adult rats, regenerated motor axons did not show any selectivity; distal muscle fibers were innervated by motoneurons whose cell bodies were distributed throughout the internal intercostal pool. However, in rats operated on at 10 d of age, distal intercostal muscle fibers were reinnervated by motoneurons that were distributed mainly in the dorsal part of the motor pool. These results support the view that positional signals may be of importance in organizing the distribution of axon terminals within muscles during development.