The human respiratory gate
Respiratory activity phasically alters membrane potentials of preganglionic vagal and sympathetic motoneurones and continuously modulates their responsiveness to stimulatory inputs. The most obvious manifestation of this ârespiratory gatingâ is respiratory sinus arrhythmia, the rhythmic fluctuat...
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Published in | The Journal of physiology Vol. 548; no. 2; pp. 339 - 352 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
Legacy CDMS
The Physiological Society
15.04.2003
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Subjects | |
Online Access | Get full text |
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Summary: | Respiratory activity phasically alters membrane potentials of preganglionic vagal and sympathetic motoneurones and continuously
modulates their responsiveness to stimulatory inputs. The most obvious manifestation of this ârespiratory gatingâ is respiratory
sinus arrhythmia, the rhythmic fluctuations of electrocardiographic RâR intervals observed in healthy resting humans. Phasic
autonomic motoneurone firing, reflecting the throughput of the system, depends importantly on the intensity of stimulatory
inputs, such that when levels of stimulation are low (as with high arterial pressure and sympathetic activity, or low arterial
pressure and vagal activity), respiratory fluctuations of sympathetic or vagal firing are also low. The respiratory gate has
a finite capacity, and high levels of stimulation override the ability of respiration to gate autonomic responsiveness. Autonomic
throughput also depends importantly on other factors, including especially, the frequency of breathing, the rate at which
the gate opens and closes. Respiratory sinus arrhythmia is small at rapid, and large at slow breathing rates. The strong correlation
between systolic pressure and RâR intervals at respiratory frequencies reflects the influence of respiration on these two
measures, rather than arterial baroreflex physiology. A wide range of evidence suggests that respiratory activity gates the
timing of autonomic motoneurone firing, but does not influence its tonic level. I propose that the most enduring significance
of respiratory gating is its use as a precisely controlled experimental tool to tease out and better understand otherwise
inaccessible human autonomic neurophysiological mechanisms. |
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Bibliography: | CDMS Legacy CDMS ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-3 content type line 23 ObjectType-Review-1 |
ISSN: | 0022-3751 1469-7793 |
DOI: | 10.1113/jphysiol.2002.037192 |