A double-hit of social and economic stress in mice precipitates changes in decision-making strategies

Abstract

Economic stress can serve as a "second-hit" for those who already accumulated a history of adverse life experiences. How one recovers from a setback is a core feature of resilience but is seldom captured in animal studies. We challenged mice in a novel two-hit stress model by exposing animals to chronic social defeat stress (first-hit) and then testing how mice adapt to reward scarcity on a neuroeconomic task (second-hit). Mice were tested longitudinally across months on the Restaurant Row task during which mice foraged daily for their sole source of food while on a limited time budget. An abrupt transition into a reward-scarce environment on this task elicits an economic crisis, precipitating a massive drop in food intake and body weight to which mice must respond in order to survive. We found that mice with a history of social defeat mounted a robust behavioral response to this economic challenge. This recovery was achieved through a complex redistribution of how time was allocated among competing opportunities via multiple valuation algorithms. Interestingly, we found that mice with a history of social defeat displayed changes in the development of decision-making policies during the recovery process important for not only ensuring food security necessary for survival but also prioritizing subjective value. These findings indicate that an individuals capacity to "bounce back" from economic stress depends on ones prior history of stress and can affect multiple aspects of subjective well-being, highlighting a motivational balance that may be altered in stress-related disorders such as depression. In BriefDurand-de Cuttoli et al. found that after chronic social defeat stress, when mice were subsequently challenged on a neuroeconomic foraging task, an economic stressor can serve as a "second hit" and reveal changes in the development of complex decision-making strategies important for maintaining the balance between food security and subjective well-being.