Author(s):
Morgado, Pedro ; Marques, Fernanda ; Ribeiro, Beatriz ; Leite-Almeida, Hugo ; Pêgo, José M. ; Rodrigues, Ana J. ; Dalla, Christina ; Kokras, Nikos ; Sousa, Nuno ; Cerqueira, João José
Date: 2015
Persistent ID: https://hdl.handle.net/1822/40680
Origin: RepositóriUM - Universidade do Minho
Project/scholarship:
info:eu-repo/grantAgreement/FCT/5876-PPCDTI/111814/PT
;
Subject(s): Decision-making; Stress; Dopamine; Quinpirole; Orbitofrontal; Insula; Science & Technology; Ciências Médicas::Ciências da Saúde
Description
Stress exposure triggers cognitive and behavioral impairments that influence decision-making processes. Decisions under a context of uncertainty require complex reward-prediction processes that are known to be mediated by the mesocorticolimbic dopamine (DA) system in brain areas sensitive to the deleterious effects of chronic stress, in particular the orbitofrontal cortex (OFC). Using a decision-making task, we show that chronic stress biases risk-based decision-making to safer behaviors. This decision-making pattern is associated with an increased activation of the lateral part of the OFC and with morphological changes in pyramidal neurons specifically recruited by this task. Additionally, stress exposure induces a hypodopaminergic status accompanied by increased mRNA levels of the dopamine receptor type 2 (Drd2) in the OFC; importantly, treatment with a D2/D3 agonist quinpirole reverts the shift to safer behaviors induced by stress on risky decision-making. These results suggest that the brain mechanisms related to risk-based decision-making are altered after chronic stress, but can be modulated by manipulation of dopaminergic transmission.
Pedro Morgado was supported by a fellowship SFRH/SINTD/60129/ 2009 funded by FCT—Foundation for Science and Technology. Supported by FEDER funds through Operational program for competitive factors - COMPETE and by national funds through FCT - Foundation for Science and Technology to project PTDC/SAU-NSC/111814/2009.
