Linked Life Data

11830281

Source:http://linkedlifedata.com/resource/pubmed/id/11830281

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2002-2-6
pubmed:abstractText
Dysfunction of the orexin/hypocretin neurotransmitter system leads to the sleep disorder narcolepsy. Narcolepsy is characterized by excessive daytime sleepiness and the occurrence of cataplexy--a sudden loss of muscle tone triggered by emotionally arousing events. Both symptoms can be treated with drugs that act on dopaminergic systems. Here we have investigated the effect of orexins on the firing of dopaminergic and GABAergic neurons of the substantia nigra (SN) in brain slices. Surprisingly, dopaminergic neurons in pars compacta were unaffected by orexins. In contrast, bath application of orexin A (100 nM) or orexin B (5-300 nM) greatly increased the firing rate of GABAergic neurons in pars reticulata. The orexin B-mediated excitation was unaffected by blocking synaptic transmission (using low-Ca2+/high-Mg2+ solution). However, the effect of orexin B was reduced significantly by thapsigargin (1 microM) and inhibitors of protein kinase A. The presence of orexinergic fibres in the SN pars reticulata was demonstrated by immunohistochemical methods with the fibre density increasing in the rostrocaudal direction. The orexin excitation of SN reticulata cells may help to maintain their high firing rate during waking. Furthermore, the absence of orexin effects in narcolepsy may predispose affected individuals to attacks of cataplexy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0167-0115
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
104
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
83-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Selective excitation of GABAergic neurons in the substantia nigra of the rat by orexin/hypocretin in vitro.
pubmed:affiliation
Institut für Neurophysiologie, Heinrich-Heine-Universität, D-40001, Düsseldorf, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't