Linked Life Data

9972774

Source:http://linkedlifedata.com/resource/pubmed/id/9972774

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-2-23
pubmed:abstractText
The nucleus raphe magnus (NRM) is an important descending inhibitory system for pain transmission. We tested whether clonidine, an alpha2-adrenergic agonist, and yohimbine, an alpha2-adrenergic antagonist, modulate the activity of NRM neurons using extracellular recording in a rat brainstem slice preparation. Clonidine 1-20 microM increased firing frequencies (FF) in 22 (37%) and decreased FF in 6 (10%) spontaneously active neurons. Correlation between the concentrations of clonidine and FF changes was unremarkable. Eight spontaneously active neurons (13%) showed increases followed by decreases in FF with increasing doses of clonidine. The remaining 24 neurons (40%) showed no change in FF. Yohimbine 1 microM decreased FF in 38 spontaneously active neurons (58%), whereas the remaining 27 neurons (42%) showed no change in FF. In some neurons, yohimbine antagonized the increase or decrease in FF by application of clonidine. In three silent neurons (25%), clonidine (5 or 10 microM) induced firing activity, which stopped or decreased with the increasing doses of clonidine. In the remaining nine neurons (75%), clonidine did not induce firing activity. We conclude that activation and inhibition of alpha2-adrenergic receptors of NRM neurons augments and suppresses output of the descending inhibitory pain pathway. Implications: The nucleus raphe magnus is implicated in descending control of the nociceptive processes. We found that clonidine and yohimbine increased and decreased, respectively, the firing activity of a substantial number of nucleus raphe magnus neurons. Clonidine and may facilitate and yohimbine may reduce the outflow of the descending inhibitory pathway.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0003-2999
pubmed:author
pubmed:issnType
Print
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
459-61
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
The effect of alpha2-adrenergic drugs on the activity of neurons in the rat nucleus raphe magnus in vitro.
pubmed:affiliation
Department of Anesthesiology and Intensive Care, Hokkaido University School of Medicine, Sapporo, Japan. kantomo@med.hokudai.ac.jp
pubmed:publicationType
Journal Article