Change of motor supply following the laryngeal nerve injury

为了确定中枢神经系统的信息如何传递到脑干中的喉运动神经元，对喉的树突分枝及其相关的中间神经元与树突的接触进行了形态学研究。1.除背外侧方向外，环甲肌的树突广泛伸展，其细胞柱的树突多向吻侧伸展，而非向尾侧伸展。环踝后运动神经元的树突构筑模式不同于其他喉内源性运动神经元。外展运动神经元的树突主要向背侧延伸至背侧呼吸群，向腹侧延伸至位于腹侧呼吸群的呼吸神经元。此外，在其细胞柱的尾侧区域还观察到许多树突更向尾侧延伸至疑似后核，该核的吻侧部分含有吸气性神经元。另一方面，内收肌的树枝晶在…中扩展更多的是背内侧、腹内侧和腹外侧方向。在内收肌细胞柱的吻部，树突主要向背内侧和腹内侧延伸，以吞噬疑核周围网状结构中的中间神经元。此外，还发现一些嘴内收肌细胞柱的树突延伸到与呼吸中心有关的Botzinger复合体。对喉固有运动神经元的树突结构进行了系统的观察，在此之前还没有报道。本研究结果提示，喉运动神经元树突的大小对喉功能有一定的影响。2.为明确喉树突与延髓内相关中间神经元之间的联系，应用免疫组织化学Fos-SP法观察喉树突与延髓内相关中间神经元的联系。用双标记法研究了对喉上神经传入电刺激作出反应的脑干下部神经元的存在。受试者在刺激后对声门关闭的反应潜伏期小于9微秒，表明孤束核(NTS)和疑核(NA)之间存在一个或两个神经元。中间神经元见于NTS周围、NTS腹侧、网状结构，靠近NA形成，也可见与内收肌树突接触。短潜伏期下的喉反射通路被认为是保护喉内呼吸道的基本组织。较少

So as to confirm how to relay information of the central nervous system to the laryngeal motoneurons in the brainstem, the laryngeal dendritic arborization and the contact between the related interneurons and dendrites were studied morphologically. 1. Dendrites of the cricothyroid muscle extended widely, except in dorsolateral direction, and most dendrites of its cell column extended rostrally rather than caudal. The pattern of dendritic architecture of posterior cricoarytenoid motoneurons differed from those of other intrinsic laryngeal motoneurons. Dendrites of the abductor motoneurons stretched mainly dorsomedially to the dorsal respiratory group and ventrolaterally to respiratory neurons located in the ventral respiratory group. In addition, many dendrites in caudal region of its cell column were observed extending more caudally to the nucleus retroambigualis, which contains inspiratory neurons in the rostral part of nucleus. A the other hand, dendrites for the adductor extended in … More dorsomedial, ventromedial and ventrolateral directions. In the rostral portion of the adductor cell columns, dendrites stretched mainly dorsomedially and ventromedially toward swallowing interneurons in the reticular formation surrounding the nucleus ambiguus. Furthermore, some dendrites of the rostral adductor cell columns were found extending to the Botzinger complex, which is related as a respiratory center. Systematic observation of the dendritic architecture of intrinsic laryngeal motoneurons has not been reported previously. The present results suggest that extent of dendrites for each laryngeal motoneurons has properties for laryngeal function. 2.To clarify connection between laryngeal dendrites and related interneurons in the medulla oblongata, Fos-immunohistochemistry was performed. The presence of neurons of the lower brainstem, that respond to the internal branch of superior laryngeal afferent electrical stimulation, was investigated by double labeling. The subjects having less than nine microsecond latency to respond glottic closure after stimulation, indicated the existence of one or two neurons between the nucleus of solitary tract (NTS) and the nucleus ambiguus (NA). Interneurons were seen in surrounding NTS, ventral to NTS and reticular, formation close to NA, and also were seen touching with the adductor dendrite. The laryngeal reflex pathway under short latency was consider as fundamental organization of protection of the airway in larynx. Less