Linked Life Data

7632985

Source:http://linkedlifedata.com/resource/pubmed/id/7632985

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-9-11
pubmed:abstractText
The rationale for the treatment of sleep disorders by scheduled exposure to bright light in seasonal affective disorder, jet lag, shift work, delayed sleep phase syndrome, and the elderly is, in part, based on a conceptual framework developed by nonclinical circadian rhythm researchers working with humans and other species. Some of the behavioral and physiological data that contributed to these concepts are reviewed, and some pitfalls related to their application to bright light treatment of sleep disorders are discussed. In humans and other mammals the daily light-dark (LD) cycle is a major synchronizer responsible for entrainment of circadian rhythms to the 24-h day, and phase response curves (PRCs) to light have been obtained. In humans, phase delays can be induced by light exposure scheduled before the minimum of the endogenous circadian rhythm of core body temperature (CBT), whereas phase advances are induced when light exposure is scheduled after the minimum of CBT. Since in healthy young subjects the minimum of CBT is located approximately 1 to 2 h before the habitual time of awakening, the most sensitive phase of the PRC to light coincides with sleep, and the timing of the monophasic sleep-wake cycle itself is a major determinant of light input to the pacemaker. The effects of light are mediated by the retinohypothalamic tract, and excitatory amino acids play a key role in the transduction of light information to the suprachiasmatic nuclei. LD cycles have direct "masking" effects on many variables, including sleep, which complicates the assessment of endogenous circadian phase and the interpretation of the effects of light treatment on sleep disorders. In some rodents motor activity has been shown to affect circadian phase, but in humans the evidence for such a feedback of activity on the pacemaker is still preliminary. The endogenous circadian pacemaker is a major determinant of sleep propensity and sleep structure; these, however, are also strongly influenced by the prior history of sleep and wakefulness. In healthy young subjects, light exposure schedules that do not curtail sleep but induce moderate shifts of endogenous circadian phase have been shown to influence the timing of sleep and wakefulness without markedly affecting sleep structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0748-7304
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
113-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Light treatment for sleep disorders: consensus report. II. Basic properties of circadian physiology and sleep regulation.
pubmed:affiliation
Institute of Pharmacology, University of Zürich, Switzerland.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't