Neural circuit mechanism of choice exploration in the basal ganglia

Abstract

Classic anatomical studies have suggested that the basal ganglia is organized into topographically segregated circuit modules controlling distinct behavior, but subserving a common computational goal. In order to test this hypothesis, we leveraged anatomical and optical tools to anatomically and functionally dissect distinct circuits within the basal ganglia. We find that all basal ganglia pathways obey the same organization principles of output connectivity. Furthermore, distinct basal ganglia pathway modulated their respective behavior in a similar fashion. By isolating the licking circuit within the basal ganglia, we further tested the computation of striatal indirect pathway during lateralized action selection. We found that striatal indirect pathway implements choice exploration via modulation of collicular dynamics, allowing mice to move away from actions that lead to a negative outcome, while exploring alternative actions. We propose a general circuit mechanism relevant across all basal ganglia pathways that allows behavioral exploration, allowing mice to optimally navigate the decision landscape.