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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1986-5-22
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pubmed:abstractText |
Single-unit recordings of 50 pressure-sensitive neurons with axonal projections to the thoracic spinal cord were obtained in the retrofacial portion of nucleus paragigantocellularis lateralis of halothane-anesthetized rats. Two types of cells were distinguished on the basis of their axonal conduction velocities: a slow-conducting (mean 0.6 m/s, group I) and a fast-conducting one (group II, mean 3.3 m/s). Both cell types were completely silenced by elevating mean arterial pressure above 160 mm Hg by means of aortic constriction and exhibited a plateau of high spontaneous activity below 70 mm Hg. Only group I neurons were significantly inhibited by the administration of clonidine in a dose producing 90% of its maximum hypotensive effect (11.5 micrograms/kg, i.v.). Hypotensive doses of clonidine administered into the fourth ventricle also produced a selective inhibition of group I neurons, while the others were unaffected. Iontophoretic applications of clonidine and norepinephrine produced an inhibition of the discharges of group I neurons qualitatively and quantitatively identical to that observed following administration of clonidine by the i.v. or i.c.v. route. Once more, group II cells were unaffected. In contrast, iontophoretically applied gamma-aminobutyric acid exerted a powerful inhibition of both cell types, an effect which was totally prevented or reversed by the gamma-aminobutyric acid antagonist bicuculline. Anatomical experiments were performed to uncover the potential source of catecholaminergic innervation of the area in which recordings were obtained. This area contains a large number of adrenaline-synthesizing neurons and receives a selective noradrenergic input from the A5 pontine group with no contribution from the A1, A2, A6 and A7 brainstem clusters of noradrenergic cells.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0006-8993
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
12
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pubmed:volume |
368
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1-17
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:3955347-Animals,
pubmed-meshheading:3955347-Arginine Vasopressin,
pubmed-meshheading:3955347-Blood Pressure,
pubmed-meshheading:3955347-Brain Mapping,
pubmed-meshheading:3955347-Clonidine,
pubmed-meshheading:3955347-Male,
pubmed-meshheading:3955347-Medulla Oblongata,
pubmed-meshheading:3955347-Neural Conduction,
pubmed-meshheading:3955347-Norepinephrine,
pubmed-meshheading:3955347-Rats,
pubmed-meshheading:3955347-Rats, Inbred Strains,
pubmed-meshheading:3955347-Spinal Cord,
pubmed-meshheading:3955347-Sympathetic Nervous System,
pubmed-meshheading:3955347-Vasomotor System,
pubmed-meshheading:3955347-gamma-Aminobutyric Acid
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pubmed:year |
1986
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pubmed:articleTitle |
Effect of clonidine and gamma-aminobutyric acid on the discharges of medullo-spinal sympathoexcitatory neurons in the rat.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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