Linked Life Data

18073333

Source:http://linkedlifedata.com/resource/pubmed/id/18073333

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-5-2
pubmed:abstractText
Daily behaviors are strongly dominated by internally generated circadian rhythms, but the underlying mechanisms remain unclear. In mammals, photoentrainment of behaviors to light-dark cycles involves signaling from both intrinsically photosensitive retinal ganglion cells and classic photoreceptor pathways to the suprachiasmatic nucleus (SCN). How classic photoreceptor pathways work with the photosensitive ganglion cells, however, is not fully understood. Although cholecystokinin (CCK) peptide has been shown to be present in a variety of vertebrate retinas, its function at a systems level is also unknown. In the present study we examined a possible role of CCK-A receptors in photoentrainment using CCK-A receptor knockout mice. The lacZ reporter gene within a gene-knockout cassette revealed precise localization of CCK-A receptors in the circadian clock system. We demonstrated that CCK-A receptors were located predominately on glycinergic amacrine cells but were rarely found on SCN neurons. Moreover, Ca(2+) imaging analysis demonstrated that the CCK-A agonist, CCK-8 sulfate (CCK-8s), mobilized intracellular Ca(2+) in amacrine cells but not glutamate-receptive SCN neurons. Furthermore, light pulse-induced mPer1/mPer2 gene expression in SCN, behavioral phase shifts, and the pupillary reflex were significantly reduced in CCK-A receptor knockout mice. These data indicate a novel function of CCK-A receptors in the nonimage-forming photoreception presumably via amacrine cell-mediated signal transduction pathways.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1479-90
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Cholecystokinin-A receptors regulate photic input pathways to the circadian clock.
pubmed:affiliation
Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't