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

This Article Full Text Full Text (PDF) All Versions of this Article: 289/5/R1338    most recent 00828.2004v1 Alert me when this article is cited 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 (3) Citing Articles via Google Scholar Google Scholar Articles by Zhang, W. Articles by Davenport, P. W. Search for Related Content PubMed PubMed Citation Articles by Zhang, W. Articles by Davenport, P. W.

ENVIRONMENTAL, EXERCISE AND RESPIRATORY PHYSIOLOGY

Respiratory muscle responses elicited by dorsal periaqueductal gray stimulation in rats

Department of Physiological Sciences, University of Florida, Gainesville, Florida

Submitted 8 December 2004 ; accepted in final form 13 June 2005

The periaqueductal gray matter is an essential neural substrate for central integration of defense behavior and accompanied autonomic responses. The dorsal half of the periaqueductal gray matter (dPAG) is also involved in mediating emotional responses of anxiety and fear, psychological states that often are associated with changes in ventilation. However, information regarding respiratory modulation elicited from this structure is limited. The present study was undertaken to investigate the relationship between stimulus frequency and magnitude on ventilatory pattern and respiratory muscle activity in urethane-anesthetized, spontaneously breathing rats. Electrical stimulation in the dPAG-recruited abdominal muscle activity increased ventilation and increased respiratory frequency by significantly shortening both inspiratory time and expiratory time. Ventilation increased within the first breath after the onset of stimulation, and the respiratory response increased with increasing stimulus frequency and magnitude. dPAG stimulation also increased baseline EMG activity in the diaphragm and recruited baseline external abdominal oblique EMG activity, normally quiescent during eupneic breathing. Significant changes in cardiorespiratory function were only evoked by stimulus intensities >10 µA and when stimulus frequencies were >10 Hz. Respiratory activity of both the diaphragm and abdominal muscles remained elevated for a minimum of 60 s after cessation of stimulation. These results demonstrate that there is a short-latency respiratory response elicited from the dPAG stimulation, which includes both inspiratory and expiratory muscles. The changes in respiratory timing suggest rapid onset and sustained poststimulus dPAG modulation of the brain stem respiratory network that includes expiratory muscle recruitment.

control of breathing; respiratory timing

This article has been cited by other articles:

				H. H. Subramanian, R. J. Balnave, and G. Holstege The Midbrain Periaqueductal Gray Control of Respiration J. Neurosci., November 19, 2008; 28(47): 12274 - 12283. [Abstract] [Full Text] [PDF]

				R. R. Strittmatter and J. C. Schadt Sex differences in the respiratory response to hemorrhage in the conscious, New Zealand white rabbit Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2007; 292(5): R1963 - R1969. [Abstract] [Full Text] [PDF]