Document Detail


Parasympathetic control of the heart. II. A novel interganglionic intrinsic cardiac circuit mediates neural control of heart rate.
MedLine Citation:
PMID:  14978001     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Intracardiac pathways mediating the parasympathetic control of various cardiac functions are incompletely understood. Several intracardiac ganglia have been demonstrated to potently influence cardiac rate [the sinoatrial (SA) ganglion], atrioventricular (AV) conduction (the AV ganglion), or left ventricular contractility (the cranioventricular ganglion). However, there are numerous ganglia found throughout the heart whose functions are poorly characterized. One such ganglion, the posterior atrial (PA) ganglion, is found in a fat pad on the rostral dorsal surface of the right atrium. We have investigated the potential impact of this ganglion on cardiac rate and AV conduction. We report that microinjections of a ganglionic blocker into the PA ganglion significantly attenuates the negative chronotropic effects of vagal stimulation without significantly influencing negative dromotropic effects. Because prior evidence indicates that the PA ganglion does not project to the SA node, we neuroanatomically tested the hypothesis that the PA ganglion mediates its effect on cardiac rate through an interganglionic projection to the SA ganglion. Subsequent to microinjections of the retrograde tracer fast blue into the SA ganglion, >70% of the retrogradely labeled neurons found within five intracardiac ganglia throughout the heart were observed in the PA ganglion. The neuroanatomic data further indicate that intraganglionic neuronal circuits are found within the SA ganglion. The present data support the hypothesis that two interacting cardiac centers, i.e., the SA and PA ganglia, mediate the peripheral parasympathetic control of cardiac rate. These data further support the emerging concept of an intrinsic cardiac nervous system.
Authors:
Alrich L Gray; Tannis A Johnson; Jeffrey L Ardell; V John Massari
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2004-02-20
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  96     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2004 Jun 
Date Detail:
Created Date:  2004-05-10     Completed Date:  2005-01-11     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2273-8     Citation Subset:  IM    
Affiliation:
Department of Pharmacology, Howard University College of Medicine, 520 W St., N.W., Washington, DC 20059, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Axonal Transport
Cats
Electrocardiography
Ganglia, Parasympathetic / physiology*
Heart / innervation*,  physiology*
Heart Conduction System / physiology*
Heart Rate / physiology*
Homeostasis
Models, Animal
Myocardial Contraction / physiology*
Grant Support
ID/Acronym/Agency:
1U54-NS-39407/NS/NINDS NIH HHS; R01-HL-51917/HL/NHLBI NIH HHS; R01-HL-58140/HL/NHLBI NIH HHS

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