Title: The role of the claustrum in flexible decision-making

Flexible decision-making is vital for survival. Animals must continuously evaluate their environment, making choices to maximize future gains. In neuropsychiatric disorders like schizophrenia, patients have difficulties in exploiting good options or exploring new ones, highlighting the importance of this cognitive ability. To facilitate decision-making, multiple brain regions represent values of choice options and update them based on environmental interactions, connecting past experiences with future plans. Yet, the neural mechanisms generating these representations remain unclear. I hypothesize that the claustrum, a subcortical nucleus highly interconnected with the neocortex, encodes decision variables and aids in sustaining their representations in cerebral cortex. First, the claustrum forms strong connections with the medial prefrontal (mPFC) and retrosplenial cortex (RSC), both representing persistent value signals, known as “decision variables”, to guide future actions. Second, the claustrum receives input from corticostriatal neurons, neurons in mPFC that encode relative value signals necessary to bias action selection. Third, recent work from our lab indicates that the claustrum generates persistent activity predicting motor behavior, potentially maintaining decision variable representations through recurrent excitation in cortico-subcortical loops.