Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 1
pubmed:dateCreated
1994-7-29
pubmed:abstractText
To determine the magnitude and direction of phase shifts of human circadian rhythms occurring within 1 day after a single exposure to bright light, plasma thyrotropin, melatonin, and cortisol levels and body temperature were monitored for 38 h in 17 men who were each studied two times, once during continuous dim light conditions and once with light exposure. After a period of entrainment to a fixed sleep-wake cycle, a 3-h light pulse (5,000 lux) was presented under constant routine conditions, and the resultant phase shifts were measured, also under constant routine conditions, on the 1st day after pulse presentation. The phase shifts in response to light occurred within 24 h and were in the delaying direction for most of the nocturnal period, with the crossover to phase advances occurring approximately 1 h after the temperature minimum. Phase shifts averaged 1 h, with delays being larger than advances, and were achieved without significant changes in rhythm amplitude. The immediate response of the human circadian clock to a single 3-h light pulse is thus characteristic of "type 1" resetting.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
E953-63
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Demonstration of rapid light-induced advances and delays of the human circadian clock using hormonal phase markers.
pubmed:affiliation
Center for the Study of Biological Rhythms, Université Libre de Bruxelles, Belgium.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't