Dorsal raphe nucleus 5-Hydroxytryptamine 2A receptors are critical for the organisation of panic attack-like defensive behaviour and unconditioned fear-induced antinociception elicited by the chemical stimulation of superior colliculus neurons

Autor(es)

Soares, Jr., Raimundo da Silva ^{[1, 2, 3]} ; Falconi-Sobrinho, Luiz Luciano ^{[1, 2, 3]} ; Almada, Rafael Carvalho ^{[1, 2]} ; Coimbra, Norberto Cysne ^{[1, 2, 3]}

Afiliação do(s) autor(es)

^[1] Behav Neurosci Inst INeC, Ave Cafe 2450, BR-14220030 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo FMRP USP, Ribeirao Preto Med Sch, Dept Pharmacol, Lab Neuroanat & Neuropsychobiol, Av Bandeirantes 3900, BR-14049900 Sao Paulo - Brazil

^[3] Univ Sao Paulo FMRP USP, Ribeirao Preto Sch Med, NAP USP Neurobiol Emot Res Ctr NuPNE, Av Bandeirantes 3900, BR-14049900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: European Neuropsychopharmacology; v. 29, n. 7, p. 858-870, JUL 2019.
• Citações Web of Science: 1

Resumo

Microinjections of N-methyl-D-aspartic acid (NMDA) in the midbrain tectum structures produce panic attack-like defensive behaviours, followed by an antinociceptive response. It has been suggested that fear-related defensive responses organised by brainstem neurons can be modulated by 5-hydroxytryptamine (5-HT). However, there is a shortage of studies showing the role of dorsal raphe nucleus (DRN) 5-HT2A receptors in the modulation of panic-like behaviour and fear-induced antinociception organised by the superior colliculus (SC). The purpose of this study was to investigate the participation of DRN 5-HT2A receptors in the modulation of panic attack-like behaviour and antinociception evoked by intra-SC injections of NMDA. In experiment I, the animals received microinjections of physiological saline or NMDA (6, 9 and 12 nmol) in the deep layers of the SC (dlSC). In experiment II, the most effective dose of NMDA (12 nmol) or vehicle was preceded by microinjections of vehicle or the 5-HT2A receptor selective antagonist R-96544 at different concentrations (0.5, 5 and 10 nM) in the DRN. Both proaversive and antinociceptive effects elicited by intra-dlSC injections of NMDA were attenuated by DRN pretreatment with R-96544. In addition, a morphological analysis showed that 5-HT2A receptors are present in GABAergic interneurons in the DRN. Taken together, these findings suggest that DRN 5-HT2A receptors are critical for the modulation of both panic attack-like defensive behaviour organised by SC neurons and unconditioned fear-induced antinociception. A possible interaction between serotonergic inputs, GABAergic interneurons and serotonergic outputs from the DRN was also considered. (C) 2019 Elsevier B.V. and ECNP. All rights reserved. (AU)

• Processo FAPESP: 07/01174-1 - Estudo do envolvimento do sistema opióide, serotoninérgico e noradrenérgico do sistema endógeno de inibição de dor em processos antinociceptivos induzidos por reações de fuga orientada evocada pela estimulação química do hipotálamo medial
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/03798-0 - Envolvimento de receptores opióides e endocanabinóides da substância negra na modulação da atividade da via GABAérgica nigro-tectal durante a organização do comportamento de defesa eliciado por roedores confrontados com serpentes veneníferas
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular