Linked Life Data

8313174

Source:http://linkedlifedata.com/resource/pubmed/id/8313174

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1994-3-23
pubmed:abstractText
Retinal input to the suprachiasmatic nuclei (SCN) and the intergeniculate leaflet (IGL) is involved in photic entrainment of mammalian circadian rhythms. The activating effects of light on firing rates of IGL cells may be regulated by serotonin (5-HT), since the IGL receives a dense serotonergic input from the midbrain raphe. We investigated the effects of 5-HT agonists and melatonin (a derivative of 5-HT) on single-unit discharges of light-sensitive cells in the hamster IGL area, using a microiontophoretic technique. 5-HT and a 5-HT1A-selective agonist, 8-OH-DPAT, potently suppressed both spontaneous and light-induced activity of IGL cells in a dose-related manner. This suppression was unchanged or potentiated by concurrently applied Mg2+, suggesting a direct action. Furthermore, the suppressive effects of both agonists were antagonized by a nonselective 5-HT antagonist, metergoline, and a 5-HT1A-directed antagonist, pindobind-5-HT1A. However, other putative 5-HT1A antagonists were weak (propranolol) or ineffective (pindolol and spiperone) in blocking the effects of 8-OH-DPAT. Neither of two 5-HT2 antagonists tested was able to block the effects of 5-HT. Melatonin generally mimicked the effects of 5-HT agonists on IGL cells, but these effects were not attenuated by 5-HT antagonists. The results indicate that both 5-HT and melatonin exert inhibitory effects on spontaneous activity and photic responses of cells in the hamster IGL, and that these effects are mediated via a 5-HT1A-like receptor and a melatonin receptor, respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
628
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8-16
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Effects of serotonin agonists and melatonin on photic responses of hamster intergeniculate leaflet neurons.
pubmed:affiliation
Department of Psychology, Dalhousie University, Halifax, Nova Scotia, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't