Anxiolytic-like effect of way-100635 microinfusions into the median (but not dorsal) raphe nucleus in mice exposed to the plus-maze: influence of prior test experience

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorCanto-De-Souza, A.
dc.creatorNunes-De-Souza, R. L.
dc.creatorRodgers, R. J.
dc.date2014-05-20T13:24:37Z
dc.date2016-10-25T16:45:21Z
dc.date2014-05-20T13:24:37Z
dc.date2016-10-25T16:45:21Z
dc.date2002-02-22
dc.date.accessioned2017-04-05T20:00:52Z
dc.date.available2017-04-05T20:00:52Z
dc.identifierBrain Research. Amsterdam: Elsevier B.V., v. 928, n. 1-2, p. 50-59, 2002.
dc.identifier0006-8993
dc.identifierhttp://hdl.handle.net/11449/7700
dc.identifierhttp://acervodigital.unesp.br/handle/11449/7700
dc.identifier10.1016/S0006-8993(01)03354-6
dc.identifierWOS:000174374800006
dc.identifierhttp://dx.doi.org/10.1016/S0006-8993(01)03354-6
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/856280
dc.descriptionStudies in several laboratories have confirmed the anxiolytic potential of a wide range of 5-HT1A receptor antagonists in rats and mice, with recent evidence pointing to a postsynaptic site of action in the ventral hippocampus. It would, therefore, be predicted that blockade of 5-HT1A somatodendritic autoreceptors in the midbrain raphe nuclei should produce anxiogenic-like effects. To test this hypothesis, we investigated the effects of WAY-100635 microinfusions (0, 1.0 or 3.0 mug in 0.1 mul) into the dorsal (DRN) or median (MRN) raphe nuclei on behaviours displayed by male Swiss-Webster mice in the elevated plus-maze. As this test is sensitive to prior experience. The effects of intra-raphe infusions were examined both in maze-naive and maze-experienced subjects. Sessions, were videotaped and subsequently scored for conventional indices of anxiety (open arm avoidance) and locomotor activity (closed arm entries), as well as a range of ethological measures (e.g. risk assessment). In maze-naive mice, intra-MRN (but not intra-DRN) infusions of WAY-100635 (3.0 mug) increased open arm exploration and reduced risk assessment. Importantly, these effects could not be attributed to a general reduction in locomotor activity. A similar, though somewhat weaker, pattern of behavioural change was observed in maze-experienced animals. This unexpected anxiolytic effect of 5-HT1A autoreceptor blockade in the MRN cannot be accounted fur by a disinhibition of 5-HT release in forebrain targets (e.g. hippocampus and amygdala), where stimulation of postsynaptic 5-HT1A receptors enhances anxiety-like responses. However, as the MRN also projects to the periaqueductal gray matter (PAG), an area known to be sensitive to the anti-aversive effects or 5-HT, it is argued that present results may reflect increased 5-HT release at this crucial midbrain locus within the neural circuitry of defense. (C) 2002 Elsevier B.V. B.V. All rights reserved.
dc.languageeng
dc.publisherElsevier B.V.
dc.relationBrain Research
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subject5-HT1A receptor
dc.subjectanxiety
dc.subjectmedian raphe nucleus
dc.subjectdorsal raphe nucleus
dc.subjectelevated plus-maze
dc.subjectWAY-100635
dc.subjectmice
dc.titleAnxiolytic-like effect of way-100635 microinfusions into the median (but not dorsal) raphe nucleus in mice exposed to the plus-maze: influence of prior test experience
dc.typeOtro


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