OPERATIONAL MECHANISMS OF AIRWAY RECEPTORS

为了完成我们以前对传入活动的研究， 我们将从喉部起源并与呼吸事件相关 记录从单一传入单位在喉返神经和 喉上上级神经的外分支。 这两条神经是 一般认为是提供传入神经支配声门下， 部分喉，而内分支的上级 喉神经（我们以前记录过）供应 声门上结构 与透壁相关的传入信息 已经发现喉中的压力和气流施加显著的 在维持上呼吸道通畅和调节呼吸中的作用 格局 冷空气，高碳酸混合物和在喉部滴入水， 发现对支气管炎活动有重要影响， 呼吸模式 我们建议研究这些挑战的影响 (and缺氧）对喉受体活性的影响， 跨壁压与喉内肌收缩 肌肉. 我们能识别水受体和二氧化碳受体吗 和我们发现的呼吸系统类型有什么联系吗 牵张受体活性不仅依赖于气道透壁性 压力，但也对平滑肌活动。 我们建议研究 牵张感受器活性与平滑肌的关系 在制备物（分离的“体内”胸外气管）中的收缩， 跨壁压保持恒定，平滑肌活动 不同（窒息、缺氧、高碳酸血症、辣椒素）。 牵张感受器 记录放电而不损害对气管的运动供应 当狗自主呼吸时，肌肉会收缩。 我们将探讨经颅压和 气道慢适应性牵张感受器的活性， 气管支气管树沿着的位置：最远端的感受器 气道可能与发生的跨壁压变化“隔离” 沿着气道。 在这种情况下，他们可以贡献一个 肺顺应性稳态的额外反射机制。

In order to complete our previous studies on the afferent activity originating from the larynx and related to respiratory events we will record from single afferent units in the recurrent laryngeal nerve and the external branch of the superior laryngeal nerve. These 2 nerves are generally thought to supply the afferent innervation to infraglottic portions of the larynx, whereas the internal branch of the superior laryngeal nerve (from which we have previously recorded) supplies supraglottic structures. Afferent information related to transmural pressure and airflow in the larynx has been found to exert a significant role in the maintenance of upper airway patency and in regulating breathing pattern. Cold air, hypercapnic mixtures and instillation of water in the larynx have been found to have important influences on bronchomotor activity and breathing pattern. We propose to study the effects of these challenges (and that of hypoxia) on the activity of laryngeal receptors activated by air flow, transmural pressure and the contraction of intrinsic laryngeal muscles. Can we identify the water receptors and carbon dioxide receptors with any of the respiratory types we have found? Stretch receptors activity depends not only on changes of airway transmural pressure, but also on smooth muscle activity. We propose to study the relationship between stretch receptor activity and smooth muscle contraction in a preparation (isolated "in vivo" extrathoracic trachea) in which transmural pressure is kept constant and smooth muscle activity is varied (asphyxia, hypoxia, hypercapnia, capsaicin). Stretch receptor discharge is recorded without impairing the motor supply to the trachealis muscle while the dog breathes spontaneously. We will explore the relationship between transpulmonary pressure and activity of airway slowly adapting stretch receptors having different locations along the tracheobronchial tree: receptors in the most distal airways may become "isolated" from transmural pressure changes occurring elsewhere along the airways. They could, in this condition, contribute an additional reflex mechanism to lung compliance homeostasis.