MCW Dysphagia Research Institute, Division of Gastroenterology and Hepatology, and Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
Am J Physiol Gastrointest Liver Physiol. 2012 Jun 15;302(12):G1445-57. doi: 10.1152/ajpgi.00007.2012. Epub 2012 Mar 8.
The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES. Reflexes were activated by stimulation of the esophagus via slow balloon or rapid air distension at 1 to 16 cm distal to the UES. Slow balloon distension consistently activated EUCR and ELIR from all areas of the esophagus, but the distal esophagus was more sensitive than the proximal esophagus. Transection of SLN or proximal recurrent laryngeal nerves (RLN) blocked EUCR and ELIR generated from the cervical esophagus. Distal RLN transection blocked EUCR from the distal cervical esophagus. Slow distension of all areas of the esophagus except the most proximal few centimeters activated secondary peristalsis, and SLN transection had no effect on secondary peristalsis. Slow distension of all areas of the esophagus inconsistently activated pharyngeal swallows, and SLN transection blocked generation of pharyngeal swallows from all levels of the esophagus. Slow distension of the esophagus inconsistently activated belching, but rapid air distension consistently activated belching from all areas of the esophagus. SLN transection did not block initiation of belch but blocked one aspect of belch, i.e., inhibition of cricopharyngeus EMG. Vagotomy blocked all aspects of belch generated from all areas of esophagus and blocked all responses of all reflexes not blocked by SLN or RLN transection. In conclusion, the SLN mediates all aspects of the pharyngeal swallow, no portion of the secondary peristalsis, and the EUCR and ELIR generated from the proximal esophagus. Considering that SLN is not a motor nerve for any of these reflexes, the role of the SLN in control of these reflexes is sensory in nature only.
本研究旨在确定喉上神经 (SLN) 在以下食管反射中的作用：食管-上食管括约肌 (UES) 收缩反射 (EUCR)、食管-下食管括约肌 (LES) 松弛反射 (ELIR)、继发性蠕动、咽吞咽和嗳气。猫（N=43）被去大脑化并进行仪器操作，以记录环咽肌、甲状舌骨肌、颏舌骨肌和环甲肌的肌电图；食管压力；以及 LES 的运动。通过在 UES 下方 1 至 16 厘米处缓慢气球或快速空气膨胀刺激食管来激活反射。缓慢气球膨胀始终从食管的所有区域激活 EUCR 和 ELIR，但远段食管比近段食管更敏感。SLN 或近端喉返神经 (RLN) 的横断阻断了来自颈段食管的 EUCR 和 ELIR。远段 RLN 横断阻断了来自远段颈段食管的 EUCR。除了最接近几厘米的近端区域外，对食管的所有区域进行缓慢膨胀都会激活继发性蠕动，而 SLN 横断对继发性蠕动没有影响。对食管的所有区域进行缓慢膨胀都会不一致地激活咽吞咽，而 SLN 横断阻断了来自食管所有水平的咽吞咽的产生。对食管进行缓慢膨胀会不一致地激活嗳气，但快速空气膨胀会从食管的所有区域一致地激活嗳气。SLN 横断并未阻断嗳气的起始，但阻断了嗳气的一个方面，即环咽肌 EMG 的抑制。迷走神经切断术阻断了来自食管所有区域的所有嗳气的各个方面，并阻断了 SLN 或 RLN 横断未阻断的所有反射的所有反应。总之，SLN 介导了咽吞咽的所有方面、没有任何部分的继发性蠕动，以及来自食管近端的 EUCR 和 ELIR。考虑到 SLN 不是这些反射的任何一个的运动神经，因此 SLN 在这些反射控制中的作用仅具有感觉性质。
