Abstract
Prior evidence suggests that the anterior cingulate cortex (ACC) is required for choosing high effort options over less effortful alternatives. Here, rats earned a high-value sucrose reward by lever pressing on a progressive ratio schedule in either the presence (choice) or absence (no-choice) of freely available, low-value lab chow. Disruption of ACC, either via chemogenetic inhibition or excitation, reduced lever pressing for high-value reward in the choice, but not in the no-choice, condition. In vivo calcium imaging revealed cell populations in ACC that selectively responded prior to lever pressing and during sucrose retrieval. These responses were significantly weaker during choice than no-choice sessions, which may have rendered them more susceptible to chemogenetic disruption. Our results suggest that neural responses in ACC encode the relative value of competing outcomes, and that the amount of effort an animal is willing to exert is proportional to the magnitude of this relative value signal.