Respiratory-related pharyngeal constrictor muscle activity in decerebrate cats

• Published in: Journal of applied physiology (1985) 1997-11, Vol.83 (5), p.1588-1594
• Main Authors: Kuna, Samuel T, Vanoye, Christi R
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cardiorespiratory control. Arterial mecano- and chemoreceptor; Cats; Decerebrate State - physiopathology; Electromyography; Female; Fundamental and applied biological sciences. Psychology; Hypercapnia - physiopathology; Hyperventilation - physiopathology; Hypoxia - physiopathology; Lung Volume Measurements; Male; Pharyngeal Muscles - physiology; Pneumothorax - physiopathology; Respiratory Mechanics - physiology; Vertebrates: respiratory system
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1997.83.5.1588

Samuel T. Kuna and Christi R. Vanoye Department of Internal Medicine, The University of Texas Medical Branch, Galveston, Texas 77555-0561 Received 20 February 1997; accepted in final form 8 July 1997. Kuna, Samuel T., and Christi R. Vanoye. Respiratory-related pharyngeal constrictor muscle activity in decerebrate cats. J. Appl. Physiol. 83(5): 1588-1594, 1997. Respiratory-related activity of the hyopharyngeus (middle pharyngeal constrictor) and thyropharyngeus (inferior pharyngeal constrictor) muscles was determined in decerebrate, tracheotomized adult cats and compared with the electromyographic activity of the thyroarytenoid, a vocal cord adductor. During quiet breathing, the hyopharyngeus and usually the thyroarytenoid exhibited phasic activity during expiration and tonic activity throughout the respiratory cycle. Respiratory-related thyropharyngeus activity was absent under these conditions. Progressive hyperoxic hypercapnia and progressive isocapnic hypoxia increased phasic expiratory activity in both pharyngeal constrictor (PC) muscles but tended to suppress thyroarytenoid activity. Passively induced hypocapnia and the central apnea that followed the cessation of the mechanical hyperventilation were associated with tonic activation of the hyopharyngeus and thyroarytenoid but no recruitment in thyropharyngeus activity. The expiratory phase of a sigh and progressive pneumothorax were associated with an increase in phasic thyroarytenoid activity but no change in phasic PC activity. The results indicate that a variety of stimuli modulate respiratory-related PC activity, suggesting that the PC muscles may have a role in the regulation of upper airway patency during respiration. hyopharyngeus; thyropharyngeus; thryoarytenoid; transversus abdominis; electromyograms 0161-7567/97 $5.00 Copyright © 1997 the American Physiological Society