Sant'Ambrogio G, Mathew O P, Sant'Ambrogio F B
Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston 77550.
Respir Physiol. 1988 Mar;71(3):287-97. doi: 10.1016/0034-5687(88)90022-9.
This study was designed to further characterize the properties of previously described laryngeal cold receptors (Respir. Physiol. 59:35, 1985). Single unit action potentials were recorded from the internal branch of the superior laryngeal nerve (SLN) in anesthetized, spontaneously breathing dogs. The nervous conduction of fibers originating from 12 laryngeal cold receptors was blocked at a mean (+/- SE) temperature of 18.8 +/- 0.7 degrees C. Twelve receptors were localized on the edge of the vocal folds in correspondence of the vocal process of the arytenoid cartilage. Topical anesthesia (2% lidocaine) blocked their activity within 4-18 sec, suggesting a superficial location. Paralysis of the vocal folds during spontaneous breathing through the upper airway did not alter the activity of 9 of 13 cold receptors. On the other hand, 7 of 12 cold receptors tested with constant flow showed respiratory modulation and laryngeal paralysis abolished the modulation of 3 of these tested with a constant flow of air. During progressive cooling in a stepwise fashion, as in frigid air breathing, laryngeal cold receptors maintained a phasic discharge. Our results indicate that these endings are particularly suited for detecting changes in temperature.
本研究旨在进一步描述先前所述喉冷感受器的特性（《呼吸生理学》59:35，1985）。在麻醉、自主呼吸的犬中，从喉上神经（SLN）内支记录单个单位动作电位。起源于12个喉冷感受器的纤维的神经传导在平均（±标准误）温度为18.8±0.7℃时被阻断。12个感受器位于对应杓状软骨声带突的声带边缘。局部麻醉（2%利多卡因）在4 - 18秒内阻断其活动，提示其位置表浅。通过上气道自主呼吸时声带麻痹并未改变13个冷感受器中9个的活动。另一方面，12个接受恒定气流测试的冷感受器中有7个表现出呼吸调制，而喉部麻痹消除了其中3个接受恒定气流测试的冷感受器的调制。在像在寒冷空气中呼吸那样逐步进行性冷却过程中，喉冷感受器保持着阶段性放电。我们的结果表明，这些末梢特别适合检测温度变化。
