Kogo N, Perry S F, Remmers J E
Department of Medical Physiology, Faculty of Medicine, University of Calgary, Health Science Centre, Alberta, Canada.
J Neurobiol. 1997 Sep;33(3):213-22. doi: 10.1002/(sici)1097-4695(199709)33:3<213::aid-neu1>3.0.co;2-4.
Using decerebrate frogs (Rana catesbeiana), we investigated the role of vagal and laryngeal sensory feedback in controlling motor activation of the larynx. Vagal and laryngeal nerve afferents were activated by electrical stimulation of the intact vagal and laryngeal nerves. Pulmonary afferents were activated by lung inflation. Reflex responses were recorded by measuring efferent activity in the laryngeal branch of the vagus (Xl) and changes in glottal aperture. Two glottic closure reflexes were identified, one evoked by lung inflation or electrical stimulation of the main branch of the vagus (Xm), and the other by electrical stimulation of Xl. Lung inflation evoked a decrementing burst of Xl efferent activity and electrical stimulation of Xm resulted in a brief burst of Xl action potentials. Electrical stimulation of Xl evoked a triphasic mechanical response, an abrupt glottal constriction followed by glottal dilatation followed by a long-lasting glottal constriction. The first phase was inferred to be a direct (nonreflex) response to the stimulus, whereas the second and third represent reflex responses to the activation of laryngeal afferents. Intracellular recordings of membrane potential of vagal motoneurons of lung and nonlung types revealed EPSPs in both types of neurons evoked by stimulation of Xm or Xl, indicating activation of glottal dilator and constrictor motoneurons. In summary, we have identified two novel reflexes producing glottic closure, one stimulated by activation of pulmonary receptors and the other by laryngeal receptors. The former may be part of an inspiratory terminating reflex and the latter may represent an airway protective reflex.
我们使用去大脑的牛蛙（牛蛙），研究了迷走神经和喉感觉反馈在控制喉部运动激活中的作用。通过电刺激完整的迷走神经和喉神经来激活迷走神经和喉神经传入纤维。通过肺充气激活肺传入纤维。通过测量迷走神经喉支（Xl）的传出活动和声门孔径的变化来记录反射反应。确定了两种声门关闭反射，一种由肺充气或迷走神经主支（Xm）的电刺激诱发，另一种由Xl的电刺激诱发。肺充气诱发Xl传出活动的递减爆发，Xm的电刺激导致Xl动作电位的短暂爆发。Xl的电刺激诱发三相机械反应，先是声门突然收缩，接着是声门扩张，然后是持续较长时间的声门收缩。第一阶段被推断为对刺激的直接（非反射）反应，而第二和第三阶段代表对喉传入纤维激活的反射反应。对肺型和非肺型迷走运动神经元膜电位的细胞内记录显示，刺激Xm或Xl在两种类型的神经元中均诱发了兴奋性突触后电位，表明声门扩张肌和收缩肌运动神经元被激活。总之，我们确定了两种产生声门关闭的新反射,一种由肺感受器激活所刺激，另一种由喉感受器刺激。前者可能是吸气终止反射的一部分，后者可能代表气道保护反射。
