Linked Life Data

15652995

Source:http://linkedlifedata.com/resource/pubmed/id/15652995

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-1-17
pubmed:abstractText
Narcolepsy-cataplexy, a disorder of excessive sleepiness and abnormalities of rapid eye movement (REM) sleep, results from deficiency of the hypothalamic orexin (hypocretin) neuropeptides. Modafinil, an atypical wakefulness-promoting agent with an unknown mechanism of action, is used to treat hypersomnolence in these patients. Fos protein immunohistochemistry has previously demonstrated that orexin neurons are activated after modafinil administration, and it has been hypothesized that the wakefulness-promoting properties of modafinil might therefore be mediated by the neuropeptide. Here we tested this hypothesis by immunohistochemical, electroencephalographic, and behavioral methods using modafinil at doses of 0, 10, 30 and 100 mg/kg i.p. in orexin-/- mice and their wild-type littermates. We found that modafinil produced similar patterns of neuronal activation, as indicated by Fos immunohistochemistry, in both genotypes. Surprisingly, modafinil more effectively increased wakefulness time in orexin-/- mice than in the wild-type mice. This may reflect compensatory facilitation of components of central arousal in the absence of orexin in the null mice. In contrast, the compound did not suppress direct transitions from wakefulness to REM sleep, a sign of narcolepsy-cataplexy in mice. Spectral analysis of the electroencephalogram in awake orexin-/- mice under baseline conditions revealed reduced power in the theta; band frequencies (8-9 Hz), an index of alertness or attention during wakefulness in the rodent. Modafinil administration only partly compensated for this attention deficit in the orexin null mice. We conclude that the presence of orexin is not required for the wakefulness-prolonging action of modafinil, but orexin may mediate some of the alerting effects of the compound.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
983-95
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15652995-Animals, pubmed-meshheading:15652995-Attention, pubmed-meshheading:15652995-Benzhydryl Compounds, pubmed-meshheading:15652995-Brain, pubmed-meshheading:15652995-Central Nervous System Stimulants, pubmed-meshheading:15652995-Dose-Response Relationship, Drug, pubmed-meshheading:15652995-Electroencephalography, pubmed-meshheading:15652995-Genotype, pubmed-meshheading:15652995-Immunohistochemistry, pubmed-meshheading:15652995-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:15652995-Male, pubmed-meshheading:15652995-Mice, pubmed-meshheading:15652995-Mice, Knockout, pubmed-meshheading:15652995-Narcolepsy, pubmed-meshheading:15652995-Neurons, pubmed-meshheading:15652995-Neuropeptides, pubmed-meshheading:15652995-Proto-Oncogene Proteins c-fos, pubmed-meshheading:15652995-Sleep, REM, pubmed-meshheading:15652995-Wakefulness
pubmed:year
2005
pubmed:articleTitle
Modafinil more effectively induces wakefulness in orexin-null mice than in wild-type littermates.
pubmed:affiliation
Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't