Role of TRPV1 channels of the dorsal periaqueductal gray in the modulation of nociception and open elevated plus maze-induced antinociception in mice

Autor(es)

Mascarenhas, Diego Cardozo ^{[1, 2]} ; Gomes, Karina Santos ^[1] ; Nunes-de-Souza, Ricardo Luiz ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista UNESP, Sch Pharmaceut Sci, BR-14801902 Araraquara, SP - Brazil

^[2] UFSCar UNESP Sao Carlos, Joint Grad Program Physiol Sci, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Behavioural Brain Research; v. 292, p. 547-554, OCT 1 2015.
• Citações Web of Science: 3

Resumo

Recent findings have identified the presence of transient receptor potential vanilloid-1 (TRPV1) channels within the dorsal portion of the periaqueductal gray (dPAG), suggesting their involvement in the control of pain and environmentally-induced antinociception. Environmentally, antinociception may be achieved through the use of an open elevated plus maze (oEPM, an EPM with 4 open arms), a highly aversive environmental situation. Here, we investigated the role of these TRPV1 channels within the dPAG in the modulation of a tonic pain and in the oEPM-induced antinociception. Male Swiss mice, under the nociceptive effect of 2.5% formalin injected into the right hind paw, received intra-dPAG injections of the TRPV1 agonist (capsaicin: 0, 0.01, 0.1 or 1.0 nmol/0.2 mu L; Experiment 1) or antagonist (capsazepine: 0, 10 or 30 nmol/0.2 mu L; Experiment 2) or combined injections of capsazepine (30 nmol) and capsaicin (1.0 nmol) (Experiment 3) and the time spent licking the formalin-injected paw was recorded. In Experiment 4, mice received intra-dPAG capsazepine (0 or 30 nmol) and were exposed to the oEPM or to a control situation, an enclosed EPM (eEPM; an EPM with 4 enclosed arms). Results showed that while capsaicin (1 nmol) decreased the time spent licking the formalin-injected paw, capsazepine did not change nociceptive response. Capsazepine (30 nmol) blocked pain inhibition induced by capsaicin and mildly attenuated the oEPM-induced antinociception. Our results revealed an important role of TRPV1 channels within the dPAG in the modulation of pain and in the phenomenon known as fear-induced antinociception in mice. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 13/06764-2 - A antinocicepção induzida pela derrota social: implicações da neurotransmissão vaniloide espinal e supraespinal em camundongos.
• Beneficiário: Diego Cardozo Mascarenhas
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/03445-3 - Efeitos da superexpressão do Fator de Liberação de Corticotropina (CRF) e nocaute de receptores Crf1 e Crf2 em regiões límbicas sobre o comportamento defensivo de camundongos: influência do estresse agudo e crônico
• Beneficiário: Karina Santos Gomes
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 13/01283-6 - Sistema hierárquico de defesa no camundongo: modulação pelo fator de liberação de corticotrofina (CRF)
• Beneficiário: Ricardo Luiz Nunes de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Regular