Document Detail


Origin of tonic GABAergic inputs to vasopressor neurons in the subretrofacial nucleus of the rabbit.
MedLine Citation:
PMID:  3209808     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The aims of this study were to determine (1) whether the vasomotor effects reflexly elicited by baroreceptor stimulation are dependent upon gamma-aminobutyric acid (GABA) receptors in the subretrofacial (SRF) nucleus in the rostral ventrolateral medulla; (2) the extent to which inputs other than those arising from peripheral baroreceptors, or transmitted via the nucleus tractus solitarius (NTS), contribute to the tonic GABAergic inhibition of SRF vasopressor cells. Following bilateral injection of a mixture of the GABA antagonist bicuculline methiodide (500 pmol) and GABA agonist muscimol (500 pmol) into the SRF nucleus, the sympathoinhibitory response normally evoked by a rise in arterial pressure (induced by inflating an aortic cuff) was abolished in 4 out of 8 rabbits and reduced in the remainder. For the whole group, the mean reduction in this response was 71%. In other experiments, the pressor response produced by injection of bicuculline methiodide into the SRF nucleus was still present after (1) destruction of the intermediate portion of the NTS, and (2) complete removal of the brain rostral to the pons. We conclude that (1) an inhibitory GABAergic input into the SRF nucleus is an important component of the central pathways mediating baroreceptor inhibition of sympathetic vasomotor tone; (2) the SRF nucleus also receives tonic GABAergic inputs that are intrinsic to the lower brainstem and are independent of baroreceptor or other cardiovascular inputs relayed by the NTS.
Authors:
R A Dampney; W W Blessing; E Tan
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of the autonomic nervous system     Volume:  24     ISSN:  0165-1838     ISO Abbreviation:  J. Auton. Nerv. Syst.     Publication Date:  1988 Oct 
Date Detail:
Created Date:  1989-02-10     Completed Date:  1989-02-10     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8003419     Medline TA:  J Auton Nerv Syst     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  227-39     Citation Subset:  IM    
Affiliation:
Department of Physiology, University of Sydney, N.S.W., Australia.
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MeSH Terms
Descriptor/Qualifier:
Animals
Aorta / innervation
Bicuculline / pharmacology
Blood Pressure / drug effects
Brain Stem / physiology
Denervation
Medulla Oblongata / physiology*
Microinjections
Neurons / physiology*
Pressoreceptors / physiology
Rabbits
Vasomotor System / physiology*
gamma-Aminobutyric Acid / physiology*
Chemical
Reg. No./Substance:
485-49-4/Bicuculline; 56-12-2/gamma-Aminobutyric Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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