Linked Life Data

18337411

Source:http://linkedlifedata.com/resource/pubmed/id/18337411

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2008-3-13
pubmed:abstractText
Arousal and maintenance of a wake state is dependent on the hypothalamic hypocretin/orexin system. We found that hypocretin neurons are depressed by opiates, drugs of abuse that reduce cognitive alertness. Met-enkephalin (mENK), an endogenous opioid, and exogenous opiates such as morphine inhibited the hypocretin system by direct actions on the cell body that include reduced spike frequency, hyperpolarization, increased G-protein-coupled inwardly rectifying K(+) channel current, and attenuated calcium current, and indirectly through reducing excitatory synaptic tone by a presynaptic mechanism. CTAP (H-d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH(2)) and naloxone, antagonists of mu-opioid receptors, blocked mu agonist actions. In the absence of exogenous opioids, mu receptor antagonists enhanced activity of the hypocretin system, suggesting ongoing inhibition by endogenous receptors. Morphine pretreatment attenuated subsequent excitatory responses to hypocretin, suggesting a long-lasting depression caused by opiate exposure. Chronic exposure to morphine reduced subsequent responses to morphine and to mENK, but increased the response to opioid receptor antagonists. Together, these data are consistent with the view that the hypocretin system may be an important direct target for drugs of abuse, including opiates, that induce sedation and mental lethargy.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
12
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2814-9
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Mu-opioid receptor-mediated depression of the hypothalamic hypocretin/orexin arousal system.
pubmed:affiliation
Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, N.I.H., Extramural