Cumulative effect of stress on decisional exploration-to-exploitation switch assessed through a gambling task in female mice

Survival and well-being hinge on an organism’s ability to evaluate options, weighing costs and benefits to make adaptive decisions. It has long been shown that stress influences cognition and reward-related behaviour, the nature of which depends on the stressor’s type and duration as well as gene x environment interactions. However, how stress influence decision-making in females has not been completely elucidated. Here, we have developed a new mouse gambling task (mGT) adapted to assess decision-making under uncertainty and risk. Adult female C57BL/6JRj mice administered with corticosterone (CORT) for 5 or 8 weeks reached similar final performance in the mGT as vehicle-treated controls. All groups tended to learn to maximize gain as the task progressed. Our results revealed that individual choice kinetics is impacted by chronic exposure to CORT, showing an accentuated sensitivity to penalties in female mice. These results confirm the suitability of our new mGT to assess decision-making under uncertainty and risk and are in line with previous reports of the effect of chronic CORT treatment on decision-making in male mice. Thereby this study provides new insights into the influence of sex and stress on decision-making.