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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6 Pt 2
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pubmed:dateCreated |
1998-2-9
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pubmed:abstractText |
We used phase plane analysis to identify modes of frequency locking of the 10-Hz rhythm in sympathetic nerve discharge (SND) to the cardiac cycle in urethan-anesthetized, baroreceptor-innervated cats. Frequency locking occurred in rational ratios predicted by a generic mathematical construct called the Farey tree. Both simple harmonic ratios (e.g., 1:3) and complex ratios (e.g., 2:5) comprised of relatively prime integers (no common divisor) were identified under natural conditions. Frequency locking in such ratios is attributed to forcing of the 10-Hz oscillator by pulse-synchronous baroreceptor afferent nerve activity (BNA). Ventricular pacing changed the frequency of the 10-Hz rhythm as well as heart rate so as to maintain or change the ratio of frequency locking in a predictable way. Intriguingly, frequency locking of the 10-Hz rhythm to medullary raphe sympathoinhibitory stimuli in simple harmonic ratios was accompanied by increased power in the 10-Hz band of SND, whereas locking in complex ratios led to decreased 10-Hz power. These findings raise the possibility that pulse-synchronous BNA also exerts divergent actions on the 10-Hz rhythm depending on the ratio of frequency locking. Augmented 10-Hz power can be attributed to the resonant properties of oscillators that are periodically forced at the same phase in their cycle.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
273
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
R1932-45
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:9435647-Activity Cycles,
pubmed-meshheading:9435647-Afferent Pathways,
pubmed-meshheading:9435647-Animals,
pubmed-meshheading:9435647-Cats,
pubmed-meshheading:9435647-Heart,
pubmed-meshheading:9435647-Heart Rate,
pubmed-meshheading:9435647-Models, Biological,
pubmed-meshheading:9435647-Neurons,
pubmed-meshheading:9435647-Pressoreceptors,
pubmed-meshheading:9435647-Raphe Nuclei,
pubmed-meshheading:9435647-Sympathetic Nervous System
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pubmed:year |
1997
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pubmed:articleTitle |
Nonlinear dynamics of the frequency locking of baroreceptor and sympathetic rhythms.
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pubmed:affiliation |
Department of Pharmacology, Michigan State University, East Lansing 48824, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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