Gore, F. et al. Nat. Neurosci. 26, 1566–1574 (2023).

Life is a constant evaluation of the outcome of our decisions and which one is more beneficial to ourselves. Therefore, economic decision-making—the process behind such choices—is critical for survival and well-being. Before any decision is taken, the individual must process the information about each option and outcome while predicting the value of each alternative. These subjective value representations have been found to be encoded primarily in the orbitofrontal cortex (OFC), and stimulating the area can affect this choice. Although other brain areas have been found to be involved in the process of decision-making behavior in rodents, little is known about how these areas interact with others. A new study in Nature Neuroscience looks at these interactions in an economic decision-making task that was adapted for rats.

After validation of the test and with rats being able to understand the two types of visual cues presented and the associated reward amount, it was possible to see that rats consistently chose larger rewards of their preferred flavor. With that knowledge and using an optogenetic inhibition approach aided by injected adeno-associated virus (AAV) in the expected areas to intervene in the process, the researchers showed that optical inhibition of the OFC and the dorsomedial striatum (DMS) impaired decision-making in the animals. When taking electrophysiological recordings of the OFC and DMS of rats making decisions, they found very similar neural encoding in both areas. Similar to what happened when inhibited, only OFC neurons seemed to strongly respond to the subjective value of the event while responding first when compared to DMS. Additionally, inhibition of OFC communication with DMS impairs decision-making when related to the volume of reward while retaining a preference for the type of reward.

Previous work suggests that activation, inactivation and injuries to brain areas such as the OFC have an effect on economic decision-making, although with contradictory results. In this new study, the researchers, by leveraging optogenetics capabilities with a new training paradigm, showed the strong role of the OFC and DMS areas and their communication for economic decision-making. These results show that economic decision-making requires weighing the subjecting value of a stimulus to choose the appropriate response, which is guided by critical anatomical areas of the brain.