Devaluing memories of reward: A case for dopamine

We describe a novel role for dopamine in devaluing sensory memories of reward. Mesencephalic dopamine cells activated during a mediated devaluation phase were later chemogenetically reactivated. This retrieval of the devalued reward memory elicited a reduction in the hedonic evaluation of sucrose reward. Through optogenetic and chemogenetic manipulations, we confirm dopamine cells are both sufficient and necessary for mediated devaluation, and retrieval of these memories reflected dopamine release in the nucleus accumbens. Consistent with our computational modelling data, our findings indicate a critical role for dopamine in encoding predictive representations of the sensory features of reinforcement. Overall, we illuminate the elaborate nature of reinforcement signals encoded by dopamine and suggest novel approaches to treating a host of psychobiological disorders.