Reflex prolongation of stage I of expiration
- 1 August 1986
- journal article
- research article
- Published by Springer Nature in Pflügers Archiv - European Journal of Physiology
- Vol. 407 (2) , 190-198
- https://doi.org/10.1007/bf00580675
Abstract
Experiments were performed on anesthetized cats to test the theory that the interval between phrenic bursts is comprised of two phases, stage I and stage II of expiration. Evidence that these represent two separate neural phases of the central respiratory rhythm was provided by the extent to which stage duration is controlled individually when tested by superior laryngeal, vagus and carotid sinus nerve stimulation. Membrane potential trajectories of bulbar postinspiratory neurons were used to identify the timing of respiratory phases. Stimulation of the superior laryngeal, vagus and carotid sinus nerves during stage I of expiration prolonged the period of depolarization in postinspiratory neurons without significantly changing the durations of either stage II expiratory or inspiratory inhibition, indicating a fairly selective prolongation of the first stage of expiration. Changes in subglottic pressure, insufflation of smoke into the upper airway, application of water to the larynx or rapid inflation of the lungs produced similar effects. Sustained tetanic stimulation of superior laryngeal and vagus nerves arrested the respiratory rhythm in stage I of expiration. Membrane potentials in postinspiratory, inspiratory and expiratory neurons were indicative of a prolonged postinspiratory period. Thus, such an arrhythmia can be described as a postinspiratory apneic state of the central oscillator. The effects of carotid sinus nerve stimulation reversed when the stimulus was applied during stage II expiration. This was accompanied by corresponding changes in the membrane potential trajectories in postinspiratory neurons. The results manifest a ternary central respiratory cycle with two individually controlled phases occurring between inspiratory bursts.This publication has 28 references indexed in Scilit:
- Function of the Larynx in the Fetus and NewbornAnnual Review of Physiology, 1984
- Apnea of Infancy and Sudden Infant Death SyndromeArchives of Pediatrics & Adolescent Medicine, 1982
- Effects of pulmonary stretch receptor blockade on laryngeal responses to hypercapnia and hypoxiaRespiration Physiology, 1981
- Effects of vagal afferents on laryngeal responses to hypercapnia and HypoxiaRespiration Physiology, 1980
- Effects of hypercapnia and hypoxia on laryngeal resistance to airflowRespiration Physiology, 1979
- Properties of inspiratory termination by superior laryngeal and vagal stimulationRespiration Physiology, 1979
- Studies on the synaptic interconnection between bulbar respiratory neurones of catsPflügers Archiv - European Journal of Physiology, 1979
- Dorsal respiratory group neurons in the medulla of cat: Spinal projections, responses to lung inflation and superior laryngeal nerve stimulationBrain Research, 1977
- Expiratory effects of brief carotid sinus nerve and carotid body stimulationsRespiration Physiology, 1976
- Activity of medullary respiratory neurones during reflexes from the lungs in catsRespiration Physiology, 1975