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的喉部运动神经元，我们从形态学上研究了喉部树突的树突化以及相关中间神经元与树突之间的联系。1. 环甲肌的树突除向背外侧外伸展广泛，其细胞柱的大部分树突向喙侧而非尾侧伸展。环杓后运动神经元的树突状结构与喉内运动神经元的树突状结构不同。外展运动神经元的树突主要向背内侧伸展至背呼吸组，向腹外侧伸展至腹呼吸组的呼吸神经元。此外，在其细胞柱尾侧区观察到许多树突向双歧后核延伸，双歧后核含有核吻侧的吸气神经元。另一方面，内收肌的树突向内侧、腹内侧和腹外方向延伸。在内收肌细胞柱的吻侧部分，树突主要向背内侧和腹内侧伸展，以吞噬模糊核周围网状结构中的中间神经元。此外，发现吻侧内收肌细胞柱的一些树突延伸到与呼吸中枢有关的Botzinger复合体。对喉内运动神经元树突状结构的系统观察尚未见报道。结果表明，喉运动神经元树突的分布范围与喉功能有关。2.为明确喉部树突与延髓内相关中间神经元之间的联系，采用免疫组化方法。用双标记法研究了对喉上传入内支电刺激有反应的下脑干神经元的存在。刺激后声门关闭反应潜伏期小于9微秒，提示孤立束核（NTS）和歧见核（NA）之间存在1 - 2个神经元。中间神经元位于NTS周围、NTS腹侧、网状、NA附近，并与内收肌树突接触。短潜伏期喉部反射通路被认为是喉部气道保护的基本组织。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