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This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 103/1/347    most recent 00211.2007v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Arshian, M. Articles by Yates, B. J. Search for Related Content PubMed PubMed Citation Articles by Arshian, M. Articles by Yates, B. J.

Consequences of postural changes and removal of vestibular inputs on the movement of air in and out of the lungs of conscious felines

Departments of ¹Otolaryngology and ²Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania; and ³Department of Otolaryngology, University of Colorado Health Sciences Center, Denver, Colorado

Submitted 20 February 2007 ; accepted in final form 7 April 2007

A variety of experimental approaches in human subjects and animal models established that the vestibular system contributes to regulation of respiration. In cats, the surgical elimination of labyrinthine signals produced changes in the spontaneous activity and posturally related responses of a number of respiratory muscles. However, these effects were complex and sometimes varied between muscle compartments, such that the physiological role of vestibulo-respiratory responses is unclear. The present study determined the functional significance of vestibulo-respiratory influences by examining the consequences of a bilateral labyrinthectomy on breathing rate and the pressure, volume, and flow rate of air exchanged during inspiration and expiration as body orientation with respect to gravity was altered. Data were collected from conscious adult cats acclimated to breathing through a facemask connected to a pneuomotach during 60° head-up pitch and ear-down roll body rotations. Removal of vestibular inputs resulted in a 15% reduction in breathing rate, a 13% decrease in minute ventilation, a 16% decrease in maximal inspiratory airflow rate, and a 14% decrease in the maximal expiratory airflow rate measured when the animals were in the prone position. However, the lesions did not appreciably affect phasic changes in airflow parameters related to alterations in posture. These results suggest that the role of the vestibular system in the control of breathing is to modify baseline respiratory parameters in proportion to the general intensity of ongoing movements, and not to rapidly alter ventilation in accordance with body position.

respiration; airway; pneumotach