Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2001-10-30
pubmed:abstractText
Hypocretins/orexins are neuropeptides implicated in sleep regulation and the sleep disorder narcolepsy. In order to examine how hypocretin activity fluctuates across 24 h with respect to the sleep-wake cycle, we measured changes in extracellular hypocretin-1 levels in the lateral hypothalamus and medial thalamus of freely moving rats with simultaneous sleep recordings. Hypocretin levels exhibited a robust diurnal fluctuation; levels slowly increased during the dark period (active phase), and decreased during the light period (rest phase). Levels were not correlated with the amount of wake or sleep in each period. Although an acute 4-h light-shift did not alter hypocretin levels, 6-h sleep deprivation significantly increased hypocretin release during the forced-wake period. Hypocretin activity is, thus, likely to build up during wakefulness and decline with the occurrence of sleep. These findings, together with the fact that a difficulty in maintaining wakefulness during the daytime is one of the primary symptoms of hypocretin-deficient narcolepsy, suggest that hypocretin activity may be critical in opposing sleep propensity during periods of prolonged wakefulness.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1075-81
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11683899-Animals, pubmed-meshheading:11683899-Carrier Proteins, pubmed-meshheading:11683899-Circadian Rhythm, pubmed-meshheading:11683899-Diencephalon, pubmed-meshheading:11683899-Down-Regulation, pubmed-meshheading:11683899-Extracellular Space, pubmed-meshheading:11683899-Hypothalamic Area, Lateral, pubmed-meshheading:11683899-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:11683899-Male, pubmed-meshheading:11683899-Microdialysis, pubmed-meshheading:11683899-Midline Thalamic Nuclei, pubmed-meshheading:11683899-Neurons, pubmed-meshheading:11683899-Neuropeptides, pubmed-meshheading:11683899-Photic Stimulation, pubmed-meshheading:11683899-Rats, pubmed-meshheading:11683899-Rats, Sprague-Dawley, pubmed-meshheading:11683899-Sleep, pubmed-meshheading:11683899-Sleep, REM, pubmed-meshheading:11683899-Sleep Deprivation, pubmed-meshheading:11683899-Up-Regulation, pubmed-meshheading:11683899-Wakefulness
pubmed:year
2001
pubmed:articleTitle
Fluctuation of extracellular hypocretin-1 (orexin A) levels in the rat in relation to the light-dark cycle and sleep-wake activities.
pubmed:affiliation
Stanford University Center for Narcolepsy, 701B Welch Rd, 1st Floor, Palo Alto, CA 94304, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.