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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.)

Activation of 5-HT2C (but not 5-H-1A) receptors in the amygdala enhances fear-induced antinociception: Blockade with local 5-H-2C antagonist or systemic fluoxetine

Texto completo
Autor(es):
Rodrigues Tavares, Ligia Renata [1, 2] ; Baptista-de-Souza, Daniela [2, 3] ; Canto-de-Souza, Azair [1, 2, 3, 4]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] UNESP, UFSCar, Joint Grad Program Physiol Sci, BR-13565905 Sao Carlos, SP - Brazil
[2] Univ Fed Sao Carlos, CECH, Dept Psychol, Psychobiol Grp, Rod Washington Luis, Km 235 Monjolinho, BR-13565905 Sao Carlos, SP - Brazil
[3] Neurosci & Behav Inst IneC, BR-14040901 Ribeirao Preto, SP - Brazil
[4] Univ Fed Sao Carlos, Psychol Program, BR-13565905 Sao Carlos, SP - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Neuropharmacology; v. 135, p. 376-385, JUN 2018.
Citações Web of Science: 1
Resumo

It is well-known that the exposure of rodents to threatening environments {[}e.g., the open arm of the elevated-plus maze (EPM)] elicits pain inhibition. Systemic and/or intracerebral {[}e.g., periaqueductal gray matter, amygdala) injections of antiaversive drugs {[}e.g., serotonin (5-HT) ligands, selective serotonin reuptake inhibitors (SSRIs)] have been used to change EPM-open arm confinement induced anti-nociception (OAA). Here, we investigated (i) the role of the 5-HT1A and 5-HT2C receptors located in the amygdaloid complex on OAA as well as (ii) the effects of systemic pretreatment with fluoxetine (an SSRI) on the effects of intra-amygdala injections of 8-OH-DPAT (a 5-HT1A agonist) or MK-212 (a 5-HT2C agonist) on nociception in mice confined to the open arm or enclosed arm of the EPM. Nociception was assessed by the writhing test. Intra-amygdala injections of 8-OH-DPAT (10 nmol) or MK-212 (0.63 nmol) produced a pronociceptive effect and intensified OAA, respectively. Fluoxetine (2.5 mg/kg, intraperitoneally) did not change 8-OH-DPAT effects on nociception but antagonized the enhancement of the OAA produced by MK-212. Interestingly, prior injection of SB 242084 (a selective 5-HT2C antagonist) into the amygdala also blocked the MK-212 effects on OAA. These results indicate that 5-HT may facilitate nociception and intensify OAA, respectively, at 5-HT1A and 5-HT2C receptors located in the amygdala of mice. The impairment produced by systemic fluoxetine on the OAA enhancement provoked by intra-amygdala MK-212 suggests that this type of fear-induced antinociception may be modulated by SSRIs. (C) 2018 Published by Elsevier Ltd. (AU)

Processo FAPESP: 09/17938-6 - Papel dos receptores serotoninérgicos da substância cinzenta periaquedutal sobre a antinocicepção de camundongos confinados aos braços abertos do labirinto em cruz elevado
Beneficiário:Daniela Baptista de Souza
Linha de fomento: Bolsas no Brasil - Doutorado Direto