Influence of a chronic ultramild stress procedure on decision-making in mice

Objective: To test the influence of a chronic ultra mild stress (CUMS) proc edure, based solely on socioenvironmental stressors, on cognitive-behaviour al function in mice. Design: Behavioural study. Participants: B6D2F1 mice. interventions: Mice were exposed to various stressors and then tested using a decision-making task. Results: We observed that stress facilitated "choi ce" behaviour, with an absence of "no choice" behaviour. Stress also facili tated a more rapid capacity to process information, a I decrease in the lev el of evaluation of the choice situation and less hesitation. These stress- related consequences on decision malting may be attributed to a higher leve l of distractability in the stressed mice. Conclusions: The GUMS model may be useful for the study of stress-related disorders by proposing a new meth od for assessing gene-environment interactions in cognitive-affective behav iours.