Action Selection and Flexible Switching Controlled by the Intralaminar Thalamic Neurons

Abstract

Summary: Learning processes contributing to appropriate selection and flexible switching of behaviors are mediated through the dorsal striatum, a key structure of the basal ganglia circuit. The major inputs to striatal subdivisions are provided from the intralaminar thalamic nuclei, including the central lateral nucleus (CL) and parafascicular nucleus (PF). Thalamostriatal neurons in the PF modulate the acquisition and performance of stimulus-response learning. Here, we address the roles of the CL thalamostriatal neurons in learning processes by using a selective neural pathway targeting technique. We show that the CL neurons are essential for the performance of stimulus-response learning and for behavioral flexibility, including reversal and attentional set-shifting of learned responses. In addition, chemogenetic suppression of neural activity supports the requirements of these neurons for behavioral flexibility. Our results suggest that the main contribution of the CL thalamostriatal neurons is functional control of the basal ganglia circuit linked to the prefrontal cortex. : Intralaminar thalamic nuclei provide the major inputs to the cortico-basal ganglia circuit. Kato et al. describe the essential roles of the thalamostriatal neurons in the CL in the performance of stimulus-response learning and in reversal and set-shifting of learned behaviors, forming a pivotal route that affects the frontostriatal circuit functions. Keywords: action selection, behavioral flexibility, intralaminar thalamic nucleus, central lateral nucleus, retrograde gene transfer, lentiviral vector, immunotoxin targeting, chemogenetics