Linked Life Data

10350528

Source:http://linkedlifedata.com/resource/pubmed/id/10350528

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1999-8-2
pubmed:abstractText
The circadian timekeeping system exhibits many functional changes with aging, including a loss of sensitivity to time cues such as systemic injections of the serotonergic agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). In order to elucidate the neurochemical mechanisms responsible for this age-related loss of sensitivity of the circadian pacemaker to serotonin agonists, the present study used quantitative autoradiography to determine whether aging decreases serotonin receptor populations in male Syrian hamsters. Four neuroanatomical regions that regulate circadian timekeeping were studied (the suprachiasmatic nuclei [SCN], the lateral geniculate nuclei [LGN], and the median raphe nucleus [MRN] and dorsal raphe nucleus [DRN]). The specific binding of [3H]8-OH-DPAT to serotonin7 (5-HT7) and serotonin1A (5-HT1A) receptors was investigated by competitive inhibition with ritanserin and pindolol, respectively. The results showed that the SCN, IGL, MRN, and DRN of the male Syrian hamster exhibited specific binding of [3H]8-OH-DPAT to both the 5-HT7 and 5-HT1A receptors, and that the latter receptor subtype is more abundant in all of these regions. At 17-19 months of age, a 50% decrease in 5-HT7 receptors was found in the DRN but not in any other regions. No significant age-related changes in 5-HT1A receptors were observed in any regions examined. The finding that a marked decrease in 5-HT7 receptors occurs in the DRN at the age previously characterized by loss of sensitivity to 8-OH-DPAT suggests that this region and this receptor subtype play important roles in 8-OH-DPAT induction of circadian phase shifts in vivo and that they constitute an important locus of aging in the circadian timing system.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-8993
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Elsevier Science B.V.
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
829
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-45
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Comparison of the effects of aging on 5-HT7 and 5-HT1A receptors in discrete regions of the circadian timing system in hamsters.
pubmed:affiliation
Department of Anatomy and Neurobiology, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536-0298, USA. mjdunc0@pop.uky.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.