Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2004-1-9
pubmed:abstractText
Nearly all circadian clocks have free-running periods that differ significantly from 24 hours. To maintain synchrony with the 24 h day, the mammalian circadian clock is reset by light. Unlike other animals, mammalian circadian entrainment occurs exclusively via the eyes and optic nerves. Remarkably, the classical photoreceptors--the rods and cones--are not necessary for photic entrainment. Instead, a subset of inner retinal ganglion cells are directly photoresponsive and transmit photic information specifically to brain centres involved in irradiance detection, including the master circadian pacemaker in the suprachiasmatic nucleus of the hypothalamus. The photopigment(s) responsible for inner retinal phototransduction are unknown. Several lines of evidence constrain candidate photopigments. First, near-total vitamin A depletion does not diminish retinohypothalamic signalling. Second, loss of cryptochrome function in retinal-degenerate mice substantially decreases photic signalling to the suprachiasmatic nucleus, and markedly decreases pupillary light responses. Third, vitamin A depletion of cryptochrome mutant mice leads to loss of photic signalling to the suprachiasmatic nucleus. These findings suggest a model where either classical photopigments or inner retinal photopigments are sufficient for non-visual irradiance detection.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1528-2511
pubmed:author
pubmed:issnType
Print
pubmed:volume
253
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31-42; discussion 42-55, 102-9, 281-4
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:14712913-Animals, pubmed-meshheading:14712913-Circadian Rhythm, pubmed-meshheading:14712913-Cryptochromes, pubmed-meshheading:14712913-Drosophila Proteins, pubmed-meshheading:14712913-Eye Proteins, pubmed-meshheading:14712913-Flavoproteins, pubmed-meshheading:14712913-Gene Expression, pubmed-meshheading:14712913-Light, pubmed-meshheading:14712913-Mice, pubmed-meshheading:14712913-Mice, Knockout, pubmed-meshheading:14712913-Models, Biological, pubmed-meshheading:14712913-Photobiology, pubmed-meshheading:14712913-Photoreceptor Cells, Invertebrate, pubmed-meshheading:14712913-Receptors, G-Protein-Coupled, pubmed-meshheading:14712913-Retina, pubmed-meshheading:14712913-Retinal Degeneration, pubmed-meshheading:14712913-Signal Transduction, pubmed-meshheading:14712913-Suprachiasmatic Nucleus
pubmed:year
2003
pubmed:articleTitle
Cryptochromes and inner retinal non-visual irradiance detection.
pubmed:affiliation
Department of Ophthalmology and Visual Sciences, Washington University Medical School, CB# 8096, 660 S. Euclid Avenue, St Louis, MO 63110, USA.
pubmed:publicationType
Journal Article