The role of dopamine in anterior cingulate cortex in the calculation of purchasing power in rats

• Applicant: Professor Dr. Tobias Kalenscher
• Subject Area: Biological Psychology and Cognitive Neuroscience
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 574125616

Research over the last decades has shown that rats comply surprisingly well to the predictions of microeconomic demand theory. We have recently designed a task meant to emulate the effects of price inflation on demand in rat consumers with or without inflation-adjusted wages. In this task, rats made effortful nose-pokes to receive chocolate or vanilla milk rewards. We manipulated, across blocks of trials, the nose-poke fixed ratio requirement to obtain chocolate or vanilla rewards (the “price” of rewards) as well as a finite daily budget of nose-pokes which rats could spend to "purchase" rewards. The budget was either kept constant when the prices of rewards changed, or it was adjusted to compensate for the changes in commodity prices. We consistently found across several studies that demand for reward was highly responsive to increases or decreases in the price of reward (demand elasticity), but, importantly, demand was significantly less elastic when the daily nose-poke budget was adjusted to compensate for price changes – a phenomenon termed budget-effect. This means that rats behaved as if they considered the purchasing power of their nose-pokes beyond the mere nominal effort costs. We recently demonstrated that the budget effect on demand was selectively abolished after lesions of the dorsal anterior cingulate cortex (dACC). In a neuroeconomic model, we hypothesized that dACC computes a higher-order value signal that reflects the utility of the quantity and composition of rewards obtained throughout a session, termed bundle utility. Here, we predict that the computation of bundle utility depends on mesocortical dopamine input into dACC. Specifically, we hypothesize that 1) the timing of dACC function is important for tracking and updating bundle utility, and 2) mesocortical dopamine input into rat dACC is necessary to produce the budget effect. We plan to test these hypotheses in a suite of several experiments, using behavioural analysis and optogenetic manipulations.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Sandra Schäble