Yamamoto Y, Ootsuka T, Atoji Y, Suzuki Y
Department of Veterinary Science, Faculty of Agriculture, Gifu University, Japan.
Anat Rec. 1998 Apr;250(4):438-47. doi: 10.1002/(SICI)1097-0185(199804)250:4<438::AID-AR7>3.0.CO;2-T.
The ganglionated nervous plexuses in the trachea play an important role in the regulation of respiration. Although the tracheal tissue of the dog has frequently been used in physiological and pharmacological studies, little is known about the morphology of the intrinsic nervous plexuses in the dog trachea and quantitative data about the ganglia and nerve cell bodies are lacking. The structure of the nervous plexuses and detailed morphometric data about the intrinsic neurons of the dog have not previously been reported.
The structure of the intrinsic nerves in the dog trachea was examined by a combination method of digestion with KOH and immunohistochemical attaining of protein gene product 9.5. In addition, areas of nerve cell profiles, numbers of nerve cell bodies per ganglion and densities of nerve cell bodies per ganglion were estimated in preparations from five dogs.
In the dog trachea, the peritracheal plexus, outer submucosal plexus, inner submucosal plexus, and mucosal plexus were identified from adventitia to epithelium in that order. The peritracheal plexus, situated in the lamina adventitia of the trachea, consisted of thick nerve bundles that were densely distributed in the membranous wall. The peritracheal plexus contained ganglia with round or oval nerve cell bodies. In the trachealis muscle, the intramuscular plexus, which was a well-developed, three-dimensional nervous network, was observed. It did not include ganglia and consisted of inter- and intrafascicular networks. The outer submucosal plexus was observed as small clusters in the inside of the trachealis muscle. A few round nerve cells were observed in the outer submucosal plexus as small clusters. The ganglionated inner submucosal plexus was identified in the superficial layer of the submucosal layer. A finer meshwork, namely, the mucosal plexus, was observed in the lamina propria. Among the entire length of the trachea, we counted 2,134-2,873 ganglia (average, 2,389) and 13,902-24,232 nerve cell bodies (average,18,461) were counted in the peritracheal plexuses of five dogs. The densities of ganglia and nerve cell bodies were high near the carina and low near the thoracic inlet. The number of nerve cell bodies per ganglion was estimated as 6.5-8.8 (average, 7.7). The average maximum area of nerve cell profiles was 522 +/- 223 microm2.
The structure of the tracheal plexuses in the dog is more complex than those in other smaller animals. The constitution of the plexuses seems to be that of the intestine. The numerous nerve cells in the peritracheal plexus in the adventitia can be expected to play important roles in airway regulation and in the pathogenesis of tracheal collapse.
气管中的神经节神经丛在呼吸调节中起重要作用。尽管犬的气管组织经常用于生理学和药理学研究，但对犬气管内固有神经丛的形态了解甚少，且缺乏关于神经节和神经细胞体的定量数据。此前尚未报道犬神经丛的结构及关于其固有神经元的详细形态计量学数据。
采用氢氧化钾消化法和蛋白质基因产物9.5免疫组织化学染色法相结合的方法，研究犬气管内固有神经的结构。此外，对5只犬的标本进行神经细胞轮廓面积、每个神经节神经细胞体数量及每个神经节神经细胞体密度的估计。
在犬气管中，从外膜到上皮依次识别出气管周围神经丛、外黏膜下神经丛、内黏膜下神经丛和黏膜神经丛。气管周围神经丛位于气管外膜层，由密集分布于膜性壁的粗大神经束组成。气管周围神经丛包含有圆形或椭圆形神经细胞体的神经节。在气管肌中，观察到肌内神经丛，它是一个发达的三维神经网络，不包含神经节，由束间和束内网络组成。外黏膜下神经丛在气管肌内部呈小簇状分布。在外黏膜下神经丛的小簇中观察到一些圆形神经细胞。在内黏膜下层的表层识别出有神经节的内黏膜下神经丛。在固有层观察到更细密的网络，即黏膜神经丛。在气管的全长范围内，我们在5只犬的气管周围神经丛中计数到2134 - 2873个神经节（平均2389个）和13902 - 24232个神经细胞体（平均18461个）。神经节和神经细胞体的密度在隆突附近较高，在胸廓入口附近较低。每个神经节神经细胞体的数量估计为6.5 - 8.8个（平均7.7个）。神经细胞轮廓的平均最大面积为522±223平方微米。
犬气管神经丛的结构比其他小型动物的更为复杂。神经丛的构成似乎与肠道的相似。外膜中气管周围神经丛中的大量神经细胞有望在气道调节和气管塌陷的发病机制中发挥重要作用。
