Involvement of D2-like dopaminergic receptors of the inferior colliculus and basolateral amygdala in the expression of conditioned and unconditioned fear in male and female rats

• Grant number: 21/04949-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2021
• End date: February 28, 2026
• Field of knowledge: Humanities - Psychology - Physiological Psychology
• Principal Investigator: Amanda Ribeiro de Oliveira
• Grantee: Camila de Oliveira Alves
• Host Institution: Centro de Educação e Ciências Humanas (CECH). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated scholarship(s): 24/03021-3 - Effects of Vagus Nerve Stimulation on the extinction of contextual conditioned fear in male and female rats, BE.EP.DR

Abstract

Several evidences indicate that dopamine is one of the most active neuromodulators in mechanisms underlying the states of fear/anxiety. Depending on the threatening condition (conditioned or unconditioned), blockade of D2-like dopaminergic receptors can reduce or increase the aversion of the situation, suggesting a dual role for dopamine in aversive states. The aim of the present study is to evaluate the effects of blocking D2 dopaminergic receptors of the Inferior Colliculus (IC) and Basolateral Amygdala (BLA) on the expression of unconditioned and conditioned fear in male and female rats, expanding the characterization of the involvement of dopaminergic neurotransmission in these structures in fear/anxiety. For this, the study will be carried out in two stages. Initially, we will carry out a systematic review of the literature in order to identify publications that have investigated the role of D2 receptors in conditioned and unconditioned fear, exploring the methodological characteristics and main findings of these studies. In the second stage, we will carry out an experimental study to evaluate the effects of the administration of sulpiride (D2 antagonist) on the IC or BLA in male and female Wistar rats submitted to the elevated plus maze test (experiment 1) and context-conditioned fear protocol (experiment 2). In general, we expect that blocking D2 dopaminergic receptors in the BLA will decrease the conditioned fear response without affecting unconditioned fear; on the other hand, with the blockade of D2 receptors in the IC, we expect to increase unconditioned defensive responses, without affecting conditioned fear. (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)

ALVES, CAMILA DE OLIVEIRA; REIMER, ADRIANO EDGAR; DE OLIVEIRA, AMANDA RIBEIRO. Involvement of D2-like dopaminergic receptors in contextual fear conditioning in female rats: influence of estrous cycle. FRONTIERS IN BEHAVIORAL NEUROSCIENCE, v. 16, p. 12-pg., 2022-11-28. (21/04949-1, 16/04620-1, 19/20274-4)

DE OLIVEIRA ALVES, CAMILA; WAKU, ISABELLE; CHIOSSI, JOYCE NONATO; DE OLIVEIRA, AMANDA RIBEIRO. Dopamine D2-like receptors on conditioned and unconditioned fear: A systematic review of rodent pharmacological studies. PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY, v. 134, p. 20-pg., 2024-07-02. (21/05022-9, 21/04949-1, 22/02986-0)