HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 99/2/691    most recent 01124.2004v1 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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Dick, T. E. Articles by Morris, K. F. Search for Related Content PubMed PubMed Citation Articles by Dick, T. E. Articles by Morris, K. F.

Arterial pulse modulated activity is expressed in respiratory neural output

¹Division of Pulmonary and Critical Care Medicine, Departments of Medicine and Neurosciences, University Hospitals Research Institute, Case Western Reserve University, Cleveland, Ohio; and ²Department of Physiology and Biophysics, University of South Florida Health Sciences Center, Tampa, Florida

Submitted 7 October 2004 ; accepted in final form 4 March 2005

Although it is well-established that sympathetic activity is modulated with respiration, it is unknown whether neural control of respiration is reciprocally influenced by cardiovascular function. Even though previous studies have suggested the existence of pulse modulation in respiratory neurons, they could not exclude the possibility that such cells were involved in cardiovascular rather than respiratory motor control, owing to neuroanatomic and functional overlaps between brain stem neurons involved in respiratory and cardiovascular control. The aim of this study was to test the hypothesis that respiratory motoneurons and putative premotoneurons are modulated by arterial pulse. An existing data set composed of 72 well-characterized, respiratory-modulated brain stem motoneurons and putative premotoneurons was analyzed using ², a recently described statistic that quantifies the magnitude of arterial pulse-modulated spike activity [Dick TE and Morris KF. J Physiol 556: 959–970, 2004]. Neuronal activity was recorded in the rostral and caudal ventral respiratory groups of 19 decerebrate, neuromuscular-blocked, ventilated cats. Axonal projections were identified by rectified and unrectified spike-triggered averages of recurrent laryngeal nerve activity or by antidromic activation from spinal stimulation electrodes. The firing rates of 30% of these neurons were modulated in phase with both the respiratory and cardiac cycles. Furthermore, arterial pulse modulation occurred preferentially in the expiratory phase in that only expiratory neurons had high ² values and only expiratory activity had significant ² values after partitioning tonic activity into the inspiratory and expiratory phases. The results demonstrate that both respiratory motoneurons and putative premotoneuronal activity can be pulse modulated. We conclude that a cardiac cycle-related modulation is expressed in respiratory motor activity, complementing the long-recognized respiratory modulation of sympathetic nerve activity.

control of respiration; homeostasis; laryngeal motoneurons; cardiorespiratory coupling

This article has been cited by other articles:

				D. M. Baekey, T. E. Dick, and J. F. R. Paton Pontomedullary transection attenuates central respiratory modulation of sympathetic discharge, heart rate and the baroreceptor reflex in the in situ rat preparation Exp Physiol, July 1, 2008; 93(7): 803 - 816. [Abstract] [Full Text] [PDF]

				Y. C. Tzeng, P. D. Larsen, and D. C. Galletly Mechanism of cardioventilatory coupling: insights from cardiac pacing, vagotomy, and sinoaortic denervation in the anesthetized rat Am J Physiol Heart Circ Physiol, April 1, 2007; 292(4): H1967 - H1977. [Abstract] [Full Text] [PDF]