Identification of the tracheal and laryngeal afferent neurones mediating cough in anaesthetized guinea-pigs
Identification of the tracheal and laryngeal afferent neurones mediating cough in anaesthetized guinea-pigs
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DOI：
10.1113/jphysiol.2003.057885
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发表时间：
2004-06-01
影响因子：
5.5
通讯作者：
Undem, BJ
中科院分区：
文献类型：
--
作者：
Canning, BJ;Mazzone, SB;Undem, BJ
我们在麻醉的豚鼠中鉴定了调节咳嗽的气管和喉传入神经。通过电刺激或机械刺激气管或喉粘膜，或通过将柠檬酸局部应用于气管或喉诱发咳嗽。相比之下，辣椒素和缓激肽对气管或喉的刺激都不会引起咳嗽。缓激肽和组胺静脉注射也未能引起咳嗽。电生理学研究表明，大多数辣椒素敏感的传入神经元（包括A-和C-纤维）支配的喙气管和喉的细胞体在颈静脉神经节和项目的气道通过上级喉神经。结状神经节内含有胞体的辣椒素不敏感传入神经元经喉返神经投射到气管和喉的嘴侧。切断喉返神经可消除气管和喉引起的咳嗽，而切断上级喉神经对咳嗽无影响。这些数据表明，气管和喉的传入神经元调节咳嗽是多模态Adelta纤维，从结状神经节。这些传入神经元被点状机械刺激和酸激活，但对辣椒素、缓激肽、平滑肌收缩、气道的纵向或横向拉伸或扩张无反应。比较这些生理特性与肺内机械感受器表明，传入神经元介导的咳嗽是相当不同的明确定义的快速和缓慢适应拉伸受体支配的气道和肺。我们认为，这些气道传入神经元代表了一个独特的亚型，其主要功能是调节咳嗽反射。
We have identified the tracheal and laryngeal afferent nerves regulating cough in anaesthetized guinea-pigs. Cough was evoked by electrical or mechanical stimulation of the tracheal or laryngeal mucosa, or by citric acid applied topically to the trachea or larynx. By contrast, neither capsaicin nor bradykinin challenges to the trachea or larynx evoked cough. Bradykinin and histamine administered intravenously also failed to evoke cough. Electrophysiological studies revealed that the majority of capsaicin-sensitive afferent neurones (both Adelta- and C-fibres) innervating the rostral trachea and larynx have their cell bodies in the jugular ganglia and project to the airways via the superior laryngeal nerves. Capsaicin-insensitive afferent neurones with cell bodies in the nodose ganglia projected to the rostral trachea and larynx via the recurrent laryngeal nerves. Severing the recurrent nerves abolished coughing evoked from the trachea and larynx whereas severing the superior laryngeal nerves was without effect on coughing. The data indicate that the tracheal and laryngeal afferent neurones regulating cough are polymodal Adelta-fibres that arise from the nodose ganglia. These afferent neurones are activated by punctate mechanical stimulation and acid but are unresponsive to capsaicin, bradykinin, smooth muscle contraction, longitudinal or transverse stretching of the airways, or distension. Comparing these physiological properties with those of intrapulmonary mechano-receptors indicates that the afferent neurones mediating cough are quite distinct from the well-defined rapidly and slowly adapting stretch receptors innervating the airways and lungs. We propose that these airway afferent neurones represent a distinct subtype and that their primary function is regulation of the cough reflex.