Neural activity in the anterior cingulate cortex is required for effort-based decision making

Adaptive decision making requires the evaluation of cost-benefit tradeoffs to guide action selection. Effort-based decision making (EBD) involves weighing predicted gains against effort costs and is disrupted in several neuropsychiatric disorders. The anterior cingulate cortex (ACC) is postulated to control effort-based choice via its role in encoding the value of overcoming effort costs in rodent EBD assays. However, temporally precise methods of manipulating neural activity have rarely been applied to EBD. We developed and validated a mouse version of the barrier T-maze EBD task, in which action selection is spatiotemporally segregated from surmounting an effortful obstacle and effort is minimally confounded with time cost. Optogenetic silencing of ACC excitatory neurons during action selection, rapidly and reversibly impaired preference to exert greater effort for a larger reward, when a less effortful alternative was available. Detailed analysis of mouse choice trajectories revealed that silencing ACC disrupts kinematics, especially prior to high effort choices. However, there were no effects on overall mobility or tendency to exert effort in non-choice assays. These findings establish causality between ACC neural activity and effortful action selection during spatial cost-benefit decision making. SIGNIFICANCE STATEMENTDisturbances in evaluating effort-based costs during decision making occur in depression, schizophrenia, addiction and Parkinsons disease. Precisely resolving the function of prefrontal brain regions in mediating these processes will reveal key loci of dysfunction and potential therapeutic intervention in these disorders.