Journal of Applied Physiology, Vol 76, Issue 3 1262-1268, Copyright © 1994 by American Physiological Society

ARTICLES

Thyroarytenoid muscle activity during hypocapnic central apneas in awake nonsedated lambs

I. Kianicka, J. F. Leroux and J. P. Praud
Department of Pediatrics, Sherbrooke University, Quebec, Canada.

In this study, we examined whether the glottis is open or closed during central apnea and the effect of arterial PO2 (PaO2) on this control. We hyperventilated nine 11- to 30-day-old awake nonsedated lambs via a tracheostomy for 1 min to induce central apnea. Four gas mixtures (8, 15, 21, and 30% O2) were used. At the end of the hyperventilation period, the lambs were allowed to breathe spontaneously through intact upper airways. Using a pneumotachograph attached to a face mask, we measured airflow, and we continuously recorded electromyographic (EMG) activity of the thyroarytenoid (TA), the main glottic adductor muscle. We also studied the lateral cricoarytenoid muscle (LCA, laryngeal adductor), the posterior cricoarytenoid muscle (PCA, laryngeal abductor), the cricothyroid muscle (CT), and the diaphragm. We found that hyperventilation consistently induced hypocapnic central apnea in all nine lambs in hyperoxic conditions [30% inspiratory fraction of O2 (FIO2)], in eight of nine lambs in normoxia or mild hypoxia (15 and 21% FIO2), and in four of seven lambs in hypoxia (8% FIO2). During baseline room air breathing, there was no glottic adductor muscle expiratory EMG activity or expiratory airflow braking. Continuous TA EMG activity began early during hyperventilation and continued throughout the central apnea, regardless of PaO2. The first subsequent breathing efforts were marked by expiratory flow braking and expiratory activity of the TA. The LCA and the TA demonstrated the same EMG activity pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				K. D. O'Halloran and G. E. Bisgard Upper airway pressure-flow relationships and pharyngeal constrictor EMG activity during prolonged expiration in awake goats J Appl Physiol, July 1, 2008; 105(1): 100 - 108. [Abstract] [Full Text] [PDF]

				F. Moreau-Bussiere, N. Samson, M. St-Hilaire, P. Reix, J. R. Lafond, E. Nsegbe, and J.-P. Praud Laryngeal response to nasal ventilation in nonsedated newborn lambs J Appl Physiol, June 1, 2007; 102(6): 2149 - 2157. [Abstract] [Full Text] [PDF]

				M. St-Hilaire, N. Samson, E. Nsegbe, C. Duvareille, F. Moreau-Bussiere, P. Micheau, J. Lebon, and J.-P. Praud Postnatal maturation of laryngeal chemoreflexes in the preterm lamb J Appl Physiol, April 1, 2007; 102(4): 1429 - 1438. [Abstract] [Full Text] [PDF]

				N. Samson, M. St-Hilaire, E. Nsegbe, P. Reix, F. Moreau-Bussiere, and J.-P. Praud Effect of nasal continuous or intermittent positive airway pressure on nonnutritive swallowing in the newborn lamb J Appl Physiol, November 1, 2005; 99(5): 1636 - 1642. [Abstract] [Full Text] [PDF]

				M. St-Hilaire, E. Nsegbe, K. Gagnon-Gervais, N. Samson, F. Moreau-Bussiere, P.-H. Fortier, and J.-P. Praud Laryngeal chemoreflexes induced by acid, water, and saline in nonsedated newborn lambs during quiet sleep J Appl Physiol, June 1, 2005; 98(6): 2197 - 2203. [Abstract] [Full Text] [PDF]

				P. Reix, J. Arsenault, C. Langlois, T. Niyonsenga, and J.-P. Praud Nonnutritive swallowing and respiration relationships in preterm lambs J Appl Physiol, October 1, 2004; 97(4): 1283 - 1290. [Abstract] [Full Text] [PDF]

				P.-H. Fortier, P. Reix, J. Arsenault, D. Dorion, and J.-P. Praud Active upper airway closure during induced central apneas in lambs is complete at the laryngeal level only J Appl Physiol, July 1, 2003; 95(1): 97 - 103. [Abstract] [Full Text] [PDF]

				P. Reix, J. Arsenault, V. Dome, P.-H. Fortier, J. R. Lafond, F. Moreau-Bussiere, D. Dorion, and J.-P. Praud Active glottal closure during central apneas limits oxygen desaturation in premature lambs J Appl Physiol, May 1, 2003; 94(5): 1949 - 1954. [Abstract] [Full Text] [PDF]

				A. A. Hutchison, D. J. Burchfield, J. A. Wozniak, and S. J. Mohrman Laryngeal Muscle Activities with Cerebral Hypoxia-Ischemia in Newborn Lambs Am. J. Respir. Crit. Care Med., July 1, 2002; 166(1): 85 - 91. [Abstract] [Full Text] [PDF]

				T. R. Feroah, H. V. Forster, L. G. Pan, and T. Rice Reciprocal activation of hypopharyngeal muscles and their effect on upper airway area J Appl Physiol, February 1, 2000; 88(2): 611 - 626. [Abstract] [Full Text] [PDF]

				K. D. O'Halloran, J. K. Herman, and G. E. Bisgard Differential effects of clonidine on upper airway abductor and adductor muscle activity in awake goats J Appl Physiol, August 1, 1999; 87(2): 590 - 597. [Abstract] [Full Text] [PDF]

				V. Diaz, D. Dorion, I. Kianicka, P. Letourneau, and J.-P. Praud Vagal afferents and active upper airway closure during pulmonary edema in lambs J Appl Physiol, May 1, 1999; 86(5): 1561 - 1569. [Abstract] [Full Text] [PDF]

				V. Diaz, D. Dorion, S. Renolleau, P. Letourneau, I. Kianicka, and J.-P. Praud Effects of capsaicin pretreatment on expiratory laryngeal closure during pulmonary edema in lambs J Appl Physiol, May 1, 1999; 86(5): 1570 - 1577. [Abstract] [Full Text] [PDF]

				S. RENOLLEAU, P. LETOURNEAU, T. NIYONSENGA, J.-P. PRAUD, and B. Gagne Thyroarytenoid Muscle Electrical Activity During Spontaneous Apneas in Preterm Lambs Am. J. Respir. Crit. Care Med., May 1, 1999; 159(5): 1396 - 1404. [Abstract] [Full Text] [PDF]

				I. Kianicka, V. Diaz, D. Dorion, and J.-P. Praud Coordination between glottic adductor muscle and diaphragm EMG activity in fetal lambs in utero J Appl Physiol, May 1, 1998; 84(5): 1560 - 1565. [Abstract] [Full Text] [PDF]

				M. S. Hedrick, M. R. Dwinell, P. L. Janssen, J. Pizarro, and G. E. Bisgard Differential respiratory muscle recruitment induced by clonidine in awake goats J Appl Physiol, April 1, 1998; 84(4): 1198 - 1207. [Abstract] [Full Text] [PDF]

				I. Kianicka, V. Diaz, S. Renolleau, E. Canet, and J.-P. Praud Laryngeal and abdominal muscle electrical activity during periodic breathing in nonsedated lambs J Appl Physiol, February 1, 1998; 84(2): 669 - 675. [Abstract] [Full Text] [PDF]

				R. P. LEMKE, N. IDIONG, S. AL-SAEDI, K. KWIATKOWSKI, D. B. CATES, and H. RIGATTO Evidence of a Critical Period of Airway Instability during Central Apneas in Preterm Infants Am. J. Respir. Crit. Care Med., February 1, 1997; 157(2): 470 - 474. [Abstract] [Full Text]