Role of the amygdala in fear-induced antinociception: behavioral, pharmacological and immunohistochemical assessments

• Grant number: 14/02956-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): June 01, 2014
• Effective date (End): May 31, 2017
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Acordo de Cooperação: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Ricardo Luiz Nunes de Souza
• Grantee: Tatiani Sorregotti
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Exposure of animals to the open elevated plus maze (oEPM : 4 open arms) elicits intense antinociceptive response, but the mechanisms , neurotransmitters and substrates are still poorly understood . In this sense, the amygdaloid complex stands out as one of the main brain regions involved in processing aversive stimuli and emotional responses related to fear, being appointed in many studies as an important site of pain modulation. Evaluation of involvement and neuronal activation amygdaloid complex through the expression of Fos protein in mice subjected to the formalin test in the paw, or exposed to oEPM, shows to be relevant for understanding the neurobiological processes involved in induced aversion antinociception (a). Since some studies indicate the presence of functional lateralization of this structure, it is important to investigate whether there is functional lateralization of the amygdaloid complex elicited responses in mice submitted to paw formalin test and exposed to the oEPM through of inactivation this structure through microinjection of cobalt chloride (CoCl2) (b). Among the neurotransmitters present in the amygdaloid complex, highlights the corticotropin-releasing factor (CRF : corticotropin-releasing factor) for playing a role in mediating the defensive and antinociceptive responses elicited by aversive stimuli. Thus, it becomes relevant to the study of CRF-érgic modulation of the amygdala in the antinociceptive response produced by exposure to oEPM (c). The experiments will be conducted five days after stereotactic surgery for implantation of intra - amygdala cannula guide: mice will be submitted or not to a nociceptive test (formalin paw), receive adequate pharmacological treatments (saline or CoCl2 unilateral and / or bilateral; saline, agonist or antagonist CRF1 or CRF2) and will be exposed to oEPM for further analysis and evaluation of defensive behaviors of nociceptive response. The brains will be removed for subsequent histological and/or Fos immunocytochemistry analysis. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SORREGOTTI, TATIANI; CIPRIANO, ANA CLAUDIA; CRUZ, FABIO CARDOSO; MASCARENHAS, DIEGO CARDOZO; RODGERS, ROBERT JOHN; NUNES-DE-SOUZA, RICARDO LUIZ. Amygdaloid involvement in the defensive behavior of mice exposed to the open elevated plus-maze. Behavioural Brain Research, v. 338, p. 159-165, FEB 15 2018. (13/06764-2, 13/24986-2, 13/01283-6, 11/04561-1, 14/02956-7)