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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Mascarenhas, Diego Cardozo [1, 2] ; Gomes, Karina Santos [1] ; Nunes-de-Souza, Ricardo Luiz [2, 1]
Total Authors: 3
[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
Total Affiliations: 2
Document type: Journal article
Source: Behavioural Brain Research; v. 292, p. 547-554, OCT 1 2015.
Web of Science Citations: 3

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)

FAPESP's process: 13/03445-3 - Effects of corticotrophin releasing factor (CRF) overexpression and Crf1 and CRF2 receptors knockout within limbic structures on defensive behavior in mice: influence of acute and chronic stress
Grantee:Karina Santos Gomes
Support type: Scholarships abroad - Research Internship - Post-doctor
FAPESP's process: 13/01283-6 - Hierarchic defensive system in mice: role of the corticotrophin-releasing factor (CRF)
Grantee:Ricardo Luiz Nunes de Souza
Support type: Regular Research Grants
FAPESP's process: 13/06764-2 - Social defeat-induced antinociception: implication of spinal and supraspinal vanilloid neurotransmission in mice.
Grantee:Diego Cardozo Mascarenhas
Support type: Scholarships in Brazil - Doctorate