Corticosterone does not change open elevated plus maze-induced antinociception in mice

Autor(es)

Mendes-Gomes, Joyce ^{[1, 2]} ; Miguel, Tarciso Tadeu ^{[2, 3]} ; Santana Amaral, Vanessa Cristiane ^{[2, 3, 4]} ; Nunes-de-Souza, Ricardo Luiz ^{[1, 2, 3]}

Afiliação do(s) autor(es)

^[1] FFCLRP USP Av, Programa Posgrad Psicobiol, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Fac Ciencias Farmaceut UNESP Rod, Lab Neuropsicofarmacol, BR-14801902 Araraquara, SP - Brazil

^[3] UFSCAR UNESP Rod, Programa Interinst Posgrad Ciencias Fisiol, BR-13565 Sao Carlos, SP - Brazil

^[4] Unidade Univ Ciencias Exatas & Tecnol, BR-75132903 Anapolis, GO - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Hormones and Behavior; v. 60, n. 4, p. 408-413, SEP 2011.
• Citações Web of Science: 8

Resumo

It has been demonstrated that the exposure of rodents to the standard elevated plus-maze (sEPM: 2 open and 2 enclosed arms) elicits defensive behavioral reactions and antinociception and also activates the hypothalamo-pituitary-adrenal (HPA) axis. We have recently reported that EPM-induced antinociception is particularly observed when rats and mice are exposed to a totally open EPM (oEPM: 4 open arms). Given that the oEPM seems to be a more aversive situation than the sEPM, we hypothesized that oEPM exposure would induce higher plasma levels of corticosterone than sEPM exposure in mice. In this study, we investigated the influence of exposure to eEPM (enclosed EPM: 4 enclosed arms), sEPM or oEPM on plasma corticosterone levels in mice, with or without prior nociceptive stimulation (2.5% formalin injection into the right hind paw). We also tested whether the nociceptive response in the formalin test and oEPM-induced antinociception are altered by adrenalectomy. Results showed that oEPM-exposed mice spent less time licking the injected paw than sEPM- and eEPM-exposed animals. All three types of EPM exposure increased plasma corticosterone when compared to the basal group, but sEPM- and oEPM-exposed mice showed higher corticosterone levels than eEPM-exposed mice. Prior nociceptive stimulation (formalin injection) did not enhance the plasma corticosterone response induced by the three types of EPM exposure. Indeed, formalin injection appeared to provoke a ceiling effect on plasma corticosterone concentration. Furthermore, neither the nociceptive response in the formalin test nor oEPM-induced antinociception was changed by adrenalectomy. Present results suggest that oEPM antinociception does not depend on corticosterone release in mice. (C) 2011 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 05/05171-1 - Papel dos mecanismos mediados pelo fator de liberação de corticotrofina e pelo complexo receptor N-metil-D-aspartato-óxido nítrico nas reações associadas a estímulos aversivos
• Beneficiário: Tarciso Tadeu Miguel
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 05/01988-3 - Papel das porções dorsal e ventrolateral da matéria cinzenta periaquedutal de camundongos na modulação das reações comportamentais defensivas e antinocicepção induzidas por situações aversivas
• Beneficiário: Joyce Mendes Gomes Tessari
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto