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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2007-7-19
pubmed:abstractText
Transgenic R6/2 mice carrying the Huntington's disease (HD) mutation show disrupted circadian rhythms that worsen as the disease progresses. By 15 weeks of age, their abnormal circadian behavior mirrors that seen in HD patients and is accompanied by dysregulated clock gene expression in the circadian pacemaker, the suprachiasmatic nucleus (SCN). We found, however, that the electrophysiological output of the SCN assayed in vitro was normal. Furthermore, the endogenous rhythm of circadian gene expression, monitored in vitro by luciferase imaging of organotypical SCN slices removed from mice with disintegrated behavioral rhythms, was also normal. We concluded that abnormal behavioral and molecular circadian rhythms observed in R6/2 mice in vivo arise from dysfunction of brain circuitry afferent to the SCN, rather than from a primary deficiency within the pacemaker itself. Because circadian sleep disruption is deleterious to cognitive function, and cognitive decline is pronounced in R6/2 mice, we tested whether circadian and cognitive disturbances could be reversed by using a sedative drug to impose a daily cycle of sleep in R6/2 mice. Daily treatment with Alprazolam reversed the dysregulated expression of Per2 and also Prok2, an output factor of the SCN that controls behavioral rhythms. It also markedly improved cognitive performance of R6/2 mice in a two-choice visual discrimination task. Together, our data show for the first time that treatments aimed at restoring circadian rhythms may not only slow the cognitive decline that is such a devastating feature of HD but may also improve other circadian gene-regulated functions that are impaired in this disease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
18
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7869-78
pubmed:meshHeading
pubmed-meshheading:17634381-Age Factors, pubmed-meshheading:17634381-Alprazolam, pubmed-meshheading:17634381-Animals, pubmed-meshheading:17634381-Cell Cycle Proteins, pubmed-meshheading:17634381-Chloral Hydrate, pubmed-meshheading:17634381-Choice Behavior, pubmed-meshheading:17634381-Circadian Rhythm, pubmed-meshheading:17634381-Cognition Disorders, pubmed-meshheading:17634381-Discrimination Learning, pubmed-meshheading:17634381-Disease Models, Animal, pubmed-meshheading:17634381-Gene Expression Regulation, pubmed-meshheading:17634381-Huntington Disease, pubmed-meshheading:17634381-Hypnotics and Sedatives, pubmed-meshheading:17634381-Mice, pubmed-meshheading:17634381-Mice, Transgenic, pubmed-meshheading:17634381-Reaction Time, pubmed-meshheading:17634381-Sleep, pubmed-meshheading:17634381-Suprachiasmatic Nucleus
pubmed:year
2007
pubmed:articleTitle
Pharmacological imposition of sleep slows cognitive decline and reverses dysregulation of circadian gene expression in a transgenic mouse model of Huntington's disease.
pubmed:affiliation
Department of Pharmacology , University of Cambridge, Cambridge CB2 1PD, United Kingdom.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't