Effects of microinjections of neurotoxin AvTx8, isolated from the social wasp Agelaia vicina (Hymenoptera, Vespidae) venom, on GABAergic nigrotectal pathways

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dc.contributor.authorOliveira, L. de
dc.contributor.authorCunha, AOS
dc.contributor.authorMortari, M. R.
dc.contributor.authorPizzo, A. B.
dc.contributor.authorMiranda, A.
dc.contributor.authorCoimbra, N. C.
dc.contributor.authorSantos, W. F. dos
dc.contributor.institutionUniversidade de São Paulo (USP)
dc.contributor.institutionUniversidade Federal de São Paulo (UNIFESP)
dc.date.accessioned2016-01-24T12:37:36Z
dc.date.available2016-01-24T12:37:36Z
dc.date.issued2005-01-07
dc.description.abstractSeveral investigations have provided information that defensive behaviors evoked by stimulation of deep layers of the superior colliculus (dISC) are subjected to inhibitory nigral modulation. This inhibition is made mainly through GABAergic neurons from substantia, nigra, pars reticulata (SNpr), that sends outputs toward neural networks of the deep layers of the superior colliculus and dorsal periaqueductal gray matter involved with the organization of fear-like responses. in this work, we compared the effects of two GABAergic agonists, muscimol and baclofen, with the effect of neurotoxin AvTx8 (1567 Da), isolated from the venom of the social wasp Agelaia vicina, microinjected into SNpr of Rattus norvegicus (Wistar rats) prior to dISC saline or bicuculline microinjections, considering that wasp venom has some influence on the uptake of GABA and/or glutamate neurotransmitters. GABA(A) receptor blockade in the dISC evoked a vigorous escape behavior, expressed by rapid running, jumps and turns, as compared to control. These defensive reactions were maximized after the intranigral GABA(A) agonism with muscimol, but not after in situ GABA(B) agonism. Nigral microinjection of AvTx8 induced similar effects to those of baclofen, decreasing the intensity of behavioral defensive reactions caused by GABA(A) receptor blockade in the dorsal mesencephalon. These findings suggest that AvTx8 has some effects on GABAergic neurotransmission, increasing the activity of the inhibitory nigrocollicular pathways, causing an anti-panic (antiaversive) effect. Therefore, our work suggests AvTx8 as a novel pharmacological tool to study differences between the two types of GABAergic receptors and excitatory amino acid-mediated mechanisms in the brain and brainstem networks. (C) 2004 Elsevier B.V. All rights reserved.en
dc.description.affiliationUSP, FFCLRP, Sch Philosophy Sci & Literature Ribeirao Preto, Dept Biol,Neurobiol & Venoms Lab, BR-14040901 Ribeirao Preto, SP, Brazil
dc.description.affiliationUSP, FFCLRP, Dept Psychol & Educ, Psychobiol Post Grad Program, BR-14040901 Ribeirao Preto, SP, Brazil
dc.description.affiliationUniversidade Federal de São Paulo, Dept Biophys, São Paulo, Brazil
dc.description.affiliationUniv São Paulo, FMRP, Sch Med Ribeirao Preto, Dept Pharmacol,Lab Neuroanat & Neuropsychobiol, BR-14049900 Ribeirao Preto, SP, Brazil
dc.description.affiliationUnifespUniversidade Federal de São Paulo, Dept Biophys, São Paulo, Brazil
dc.description.sourceWeb of Science
dc.format.extent74-81
dc.identifierhttp://dx.doi.org/10.1016/j.brainres.2004.10.027
dc.identifier.citationBrain Research. Amsterdam: Elsevier B.V., v. 1031, n. 1, p. 74-81, 2005.
dc.identifier.doi10.1016/j.brainres.2004.10.027
dc.identifier.issn0006-8993
dc.identifier.urihttp://repositorio.unifesp.br/handle/11600/28111
dc.identifier.wosWOS:000226422700008
dc.language.isoeng
dc.publisherElsevier B.V.
dc.relation.ispartofBrain Research
dc.rightsinfo:eu-repo/semantics/restrictedAccess
dc.rights.licensehttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.subjectwasp venomen
dc.subjectsubstantia nigraen
dc.subjectGABA(A) receptoren
dc.subjectGABA(B) receptoren
dc.subjectGABAergic striato-nigro-tectal pathwaysen
dc.subjectexcitatory amino acid-mediated mechanismsen
dc.titleEffects of microinjections of neurotoxin AvTx8, isolated from the social wasp Agelaia vicina (Hymenoptera, Vespidae) venom, on GABAergic nigrotectal pathwaysen
dc.typeinfo:eu-repo/semantics/article
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