B. J. Canning: Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
J Physiol. 2013 Sep 15;591(18):4667-79. doi: 10.1113/jphysiol.2013.256024. Epub 2013 Jul 15.
We describe swallowing reflexes evoked by laryngeal and tracheal vagal afferent nerve stimulation in anaesthetized guinea pigs. The swallowing reflexes evoked by laryngeal citric acid challenges were abolished by recurrent laryngeal nerve (RLN) transection and mimicked by electrical stimulation of the central cut ends of an RLN. By contrast, the number of swallows evoked by upper airway/pharyngeal distensions was not significantly reduced by RLN transection but they were virtually abolished by superior laryngeal nerve transection. Laryngeal citric acid-evoked swallowing was mimicked by laryngeal capsaicin challenges, implicating transient receptor potential vanilloid 1 (TRPV1)-expressing laryngeal afferent nerves arising from the jugular ganglia. The swallowing evoked by citric acid and capsaicin and evoked by electrical stimulation of either the tracheal or the laryngeal mucosa occurred at stimulation intensities that were typically subthreshold for evoking cough in these animals. Swallowing evoked by airway afferent nerve stimulation also desensitized at a much slower rate than cough. We speculate that swallowing is an essential component of airway protection from aspiration associated with laryngeal and tracheal afferent nerve activation.
我们描述了麻醉豚鼠的喉和气管迷走传入神经刺激诱发的吞咽反射。喉柠檬酸刺激诱发的吞咽反射被喉返神经（RLN）切断所消除，并且可以通过 RLN 中央切断端的电刺激来模拟。相比之下，上气道/咽扩张引起的吞咽次数并没有被 RLN 切断显著减少，但它们几乎被喉上神经切断所消除。喉柠檬酸刺激诱发的吞咽可以被喉辣椒素挑战所模拟，暗示了来自颈静脉神经节的表达瞬时受体电位香草素 1（TRPV1）的喉传入神经的参与。柠檬酸和辣椒素刺激以及气管或喉黏膜电刺激诱发的吞咽，其刺激强度通常低于这些动物咳嗽的阈强度。气道传入神经刺激诱发的吞咽也比咳嗽的脱敏速度慢得多。我们推测，吞咽是防止与喉和气管传入神经激活相关的吸入性误吸的重要组成部分。
