Effects Of Naltrexone And Cross-tolerance To Morphine In A Learned Helplessness Paradigm.

dc.creatorTeixeira, N A
dc.creatorPereira, D G
dc.creatorHermini, A H
dc.date1997-Jun
dc.date2015-11-27T12:19:00Z
dc.date2015-11-27T12:19:00Z
dc.date.accessioned2018-03-29T00:52:19Z
dc.date.available2018-03-29T00:52:19Z
dc.identifierBrazilian Journal Of Medical And Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas / Sociedade Brasileira De Biofísica ... [et Al.]. v. 30, n. 6, p. 775-82, 1997-Jun.
dc.identifier0100-879X
dc.identifier
dc.identifierhttp://www.ncbi.nlm.nih.gov/pubmed/9292116
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/194053
dc.identifier9292116
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1294286
dc.descriptionOpiates have been implicated in learned helplessness (LH), a phenomenon known to be related to opiate stress-induced analgesia (SIA). In the present study, we investigated the role of opiates in the induction of LH and SIA under different conditions. Adult female Wistar rats were trained either by receiving 60 inescapable 1-mA footshocks (IS group, N = 114) or by confinement in the shock box (control or NS group, N = 92). The pain threshold of some of the animals was immediately evaluated in a tail-flick test while the rest were used 24 h later in a shuttle box experiment to examine their escape performance. The opiate antagonist naltrexone (0 or 8 mg/kg, ip) and the previous induction of cross-tolerance to morphine by the chronic administration of morphine (0 or 10 mg/kg, sc, for 13 days) were used to identify opiate involvement. Analysis of variance revealed that only animals in the IS group demonstrated antinociception and an escape deficit, both of which were resistant to the procedures applied before the training session. However, the escape deficit could be reversed if the treatments were given before the test session. We conclude that, under our conditions, induction of the LH deficit in escape performance is not opiate-mediated although its expression is opiate-modulated.
dc.description30
dc.description775-82
dc.languageeng
dc.relationBrazilian Journal Of Medical And Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas / Sociedade Brasileira De Biofísica ... [et Al.]
dc.relationBraz. J. Med. Biol. Res.
dc.rightsaberto
dc.rights
dc.sourcePubMed
dc.subjectAnalgesia
dc.subjectAnalgesics, Opioid
dc.subjectAnimals
dc.subjectDrug Tolerance
dc.subjectFemale
dc.subjectHelplessness, Learned
dc.subjectMorphine
dc.subjectNaltrexone
dc.subjectNarcotic Antagonists
dc.subjectRats
dc.subjectRats, Wistar
dc.titleEffects Of Naltrexone And Cross-tolerance To Morphine In A Learned Helplessness Paradigm.
dc.typeArtículos de revistas


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