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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

MEDIAL PREFRONTAL CORTEX SEROTONERGIC AND GABAERGIC MECHANISMS MODULATE THE EXPRESSION OF CONTEXTUAL FEAR: INTRATELENCEPHALIC PATHWAYS AND DIFFERENTIAL INVOLVEMENT OF CORTICAL SUBREGIONS

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Autor(es):
Almada, R. C. [1, 2] ; Coimbra, N. C. [1, 3, 2] ; Brandao, M. L. [1, 3, 4]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Inst Neurosci & Behav INeC, BR-14050220 Sao Paulo - Brazil
[2] Univ Sao Paulo FMRP USP, Ribeirao Preto Med Sch, Dept Pharmacol, Lab Neuroanat & Neuropsychobiol, Sao Paulo - Brazil
[3] Univ Sao Paulo, Ribeirao Preto Med Sch, NAP USP Neurobiol Emot Res Ctr NuPNE, Sao Paulo - Brazil
[4] Univ Sao Paulo, Dept Psychol, Sch Philosophy Sci & Literature, Lab Neuropsychopharmacol, Sao Paulo - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Neuroscience; v. 284, p. 988-997, JAN 22 2015.
Citações Web of Science: 18
Resumo

Several lines of evidence indicate that the dorsal hippocampus (dH) and medial prefrontal cortex (mPFC) regulate contextual fear conditioning. The prelimbic (PrL), infralimbic (IL) and the anterior cingulate cortex (ACC) subregions of the mPFC likely play distinct roles in the expression of fear. Moreover, studies have highlighted the role of serotonin (5-hydroxytryptamine, 5-HT)- and gamma-aminobutyric acid (GABA)- mediated mechanisms in the modulation of innate fear in the mPFC. The present study characterized dH-mPFC pathways and investigated the role of serotonergic and GABAergic mechanisms of the PrL, IL and ACC-area 1 (Cg1) in the elaboration of contextual fear conditioning using fear-potentiated startle (FPS) and freezing behavior in Rattus norvegicus. The results of neurotracing with microinjections of biotinylated dextran amine into the dH revealed a neural link of the dH with the PrL and ACC. Intra-PrL injections of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) and the GABA(A) receptor-selective agonist muscimol reduced contextual FPS and freezing responses. Intra-Cg1 injections of muscimol but not 8-OH-DPAT decreased FPS and freezing responses. However, neither intra-IL injections of a 5-HT1A agonist nor of a GABA(A) agonist affected these defensive responses. Labeled neuronal fibers from the dH reached the superficial layers of the PrL cortex and spread to the inner layers of PrL and Cg1 cortices, supporting the pharmacological findings. The present results confirmed the involvement of PrL and Cg1 in the expression of FPS and freezing responses to aversive conditions. In addition, PrL serotoninergic mechanisms play a key role in contextual fear conditioning. This study suggests that PrL, IL and Cg1 distinctively contribute to the modulation of contextual fear conditioning. (C) 2014 IBRO. Published by Elsevier Ltd. All rights reserved. (AU)

Processo FAPESP: 11/00041-3 - Neurobiologia do estresse: a interface sensório-motora
Beneficiário:Marcus Lira Brandão
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 12/22681-7 - Envolvimento de receptores opióides e endocanabinóides da substância negra, parte reticulada, na modulação da atividade da via GABAérgica nigro-tectal durante a organização do comportamento defensivo de camundongos confrontados com serpentes veneníferas
Beneficiário:Rafael Carvalho Almada
Linha de fomento: Bolsas no Brasil - Pós-Doutorado