Influence of intralaryngeal CO, on the response of laryngeal afferents to upper airway negative pressure

intralaryngeal CO2 on the response of laryngeal afferents to upper airway negative pressure. J. Appl. Physiol. 76(6): 2720-2725, 1994.-Effects of intralaryngeal CO, on the response of superior laryngeal afferents to negative pressure were investi-gated in 20 anesthetized spontaneously breathing adult cats. Single-fiber action potentials were recorded from the periph-eral cut end of the superior laryngeal nerve. The larynx was exposed to negative pressure during inspiration when the ani-mal breathed against an occluded upper airway. Among the 99 receptors evaluated, 54 were respiratory modulated and 45 were nonmodulated endings. The effect of intralaryngeal CO, on the response of 39 receptors responding to negative pressure was determined by exposure of the larynx to CO, or air for 1 min followed immediately by upper airway occlusion. The mean discharge frequency of 22 fibers inhibited by negativ