Bieger D, Hopkins D A
Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
J Comp Neurol. 1987 Aug 22;262(4):546-62. doi: 10.1002/cne.902620408.
The nucleus ambiguus has been reported to innervate various thoracic and abdominal viscera in addition to the musculature of the upper alimentary tract. However, the literature is contradictory as to how different regions of the nucleus ambiguus innervate specific organs. Therefore, a systematic investigation of the viscerotopic organization of the nucleus ambiguus was undertaken. In 102 rats, 0.5-10.0 microliter of HRP, WGA-HRP, cholera toxin-HRP or fluorescent tracers were injected into the IXth, Xth, and XIth cranial nerves and the major branches of the Xth as well as organs supplied by them. The results demonstrate that the nucleus ambiguus in the rat is made up of two major longitudinal divisions: a dorsal division comprised of three rostrocaudally aligned subdivisions representing the special visceral efferent component, and a ventral division comprised of at least two subdivisions representing the general visceral efferent component. The dorsal division corresponds to the nucleus ambiguus in the narrow sense and comprises a rostral esophagomotor compact formation, an intermediate pharyngolaryngomotor semicompact formation, and a caudal laryngomotor loose formation. Each of these formations displays a characteristic dendroarchitecture. The stylopharyngeal and cricothyroid motoneurons are displaced rostrad from the main pharyngeal and laryngeal motoneuronal pools. Thyropharyngeal (lower constrictor) motoneurons occupy the rostral half of the semi-compact formation and hyopharyngeal (middle constrictor) motoneurons its entire length. The ventral division of the nucleus ambiguus corresponds to the external formation, extends along the entire length of the medulla oblongata, and contains preganglionic neurons innervating the heart and supradiaphragmatic structures innervated by the glossopharyngeal and the superior laryngeal nerves.
据报道，疑核除了支配上消化道的肌肉组织外，还支配各种胸腹部内脏器官。然而，关于疑核的不同区域如何支配特定器官，文献中的说法相互矛盾。因此，对疑核的内脏定位组织进行了系统研究。在102只大鼠中，将0.5 - 10.0微升的辣根过氧化物酶（HRP）、小麦胚凝集素-辣根过氧化物酶（WGA-HRP）、霍乱毒素-辣根过氧化物酶或荧光示踪剂注入第九、第十和第十一颅神经以及第十颅神经的主要分支及其所支配的器官。结果表明，大鼠的疑核由两个主要的纵向分区组成：一个背侧分区，由三个 rostrocaudally 排列的亚分区组成，代表特殊内脏传出成分；一个腹侧分区，由至少两个亚分区组成，代表一般内脏传出成分。背侧分区相当于狭义的疑核，包括一个嘴侧食管运动致密结构、一个中间咽喉运动半致密结构和一个尾侧喉运动疏松结构。这些结构中的每一个都显示出独特的树突结构。茎突咽肌和环甲肌运动神经元从主要的咽和喉运动神经元池向嘴侧移位。甲状腺咽肌（下缩肌）运动神经元占据半致密结构的嘴侧一半，舌咽肌（中缩肌）运动神经元占据其全长。疑核的腹侧分区相当于外侧结构，沿延髓全长延伸，并包含支配心脏和由舌咽神经和喉上神经支配的膈上结构的节前神经元。
