Mathew O P, Sant'Ambrogio G, Fisher J T, Sant'Ambrogio F B
Respir Physiol. 1984 Oct;58(1):41-50. doi: 10.1016/0034-5687(84)90043-4.
This study evaluates the afferent activity in the superior laryngeal nerve (SLN) during breathing as well as during occluded inspiratory efforts. Experiments were performed in 11 anesthetized and spontaneously breathing dogs. Electroneurographic activity was recorded from the peripheral cut end of the SLN and, in 3 dogs, also from the contralateral vagus nerve. A tracheal cannula with a side arm allowed the bypass of the larynx during breathing and occluded efforts. A clear inspiratory modulation was present in all experimental conditions. Both peak and duration of the SLN activity decreased (87% and 89%) when breathing was diverted from the upper airway to the tracheostomy. Peak and duration of the SLN activity (as % of upper airway breathing) increased during occluded efforts; however, the increase was greater when the larynx was not by-passed (peak = 118% vs 208%, duration = 143% vs 178%). Section of the ipsilateral recurrent laryngeal nerve reduced the inspiratory modulation. Vagal afferent activity increased equally during tracheostomy and upper airway breathing and decreased markedly during tracheal and upper airway occlusions. Our results indicate that collapsing pressure in the larynx is the major stimulus in activating laryngeal afferents.
本研究评估了在呼吸过程以及吸气受阻时喉上神经（SLN）的传入活动。实验在11只麻醉且自主呼吸的犬身上进行。从SLN的外周切断端记录神经电图活动，在3只犬中还从对侧迷走神经记录。带有侧臂的气管插管可在呼吸和吸气受阻时绕过喉部。在所有实验条件下均存在明显的吸气调制。当呼吸从上部气道转向气管造口时，SLN活动的峰值和持续时间均下降（分别下降87%和89%）。在吸气受阻时，SLN活动的峰值和持续时间（相对于上部气道呼吸的百分比）增加；然而，当喉部未被绕过（峰值 = 118%对208%，持续时间 = 143%对178%）时增加幅度更大。切断同侧喉返神经可降低吸气调制。在气管造口和上部气道呼吸时迷走神经传入活动同等增加，而在气管和上部气道阻塞时显著下降。我们的结果表明，喉部的塌陷压力是激活喉传入神经的主要刺激因素。
