The rostral intralaminar nuclear complex of the thalamus supports striatally-mediated action reinforcement

Abstract

The dorsal striatum (DS) mediates the selection of actions for reward acquisition necessary for survival. Striatal pathology contributes to several neuropsychiatric conditions, including aberrant selection of actions for specific rewards in addiction. A major source of glutamate driving striatal activity is the rostral intralaminar nuclei of the thalamus (rILN). Yet, the information that is relayed to the striatum to support action selection is unknown. Here we discovered that rILN neurons projecting to the DS integrated information from several subcortical and cortical sources and that these rILN-to-DS neurons stably signaled at two time points in mice performing an action sequence task reinforced by sucrose reward: action initiation and reward acquisition.In vivoactivation of this pathway increased the number of successful trials whereas inhibition decreased the number of successful trials. These findings illuminate a role for the rostral intralaminar nuclear complex in reinforcing actions.