Dynamic neuronal activation of a distributed cortico-basal ganglia-thalamus loop in learning a delayed sensorimotor task

Abstract

The cortico-basal ganglia-thalamus (CBT) loop is important for behavior. However, the activity and learning-related modulation within the loop in behavior remain unclear. To tackle this problem, we trained mice to perform a delayed sensorimotor-transformation task and recorded single-unit activity during learning simultaneously from four regions in a CBT loop: prelimbic area (PrL), posterior premotor cortex (pM2), dorsomedial caudate/putamen (dmCP), and mediodorsal thalamus (MD). Sensory and decision related information were encoded by the neurons within the loop, with weak interaction among neurons of different coding ability. The functional interaction among regions within the loop was dynamically routed in the loop during different behavioral phases and contributed to explain decision-related neuronal activity. The neurons of PrL and dmCP exhibited learning-related reorganization in neuronal activity and more persistent coding of sensory and decision-related information. Thus, both sensory- and decision-related information are processed in a functionally interacted CBT loop that is modulated by learning.