Cell-type-specific sustained value representations in the claustrum.

Flexible decision-making relies on interactions between frontal cortex and subcortical structures. The claustrum, a subcortical nucleus highly interconnected with frontal cortex, influences cortical activity and has been implicated in cognitive functions. Recording from claustrum neurons as mice performed a reinforcement learning task, we found that the activity of almost half of recorded neurons scaled with reward rate and predicted trial-by-trial adjustments in reaction time and choice switching. Individual neurons sustained this activity over seconds between trials. Our recordings identified two electrophysiologically distinct populations. One was excited during task execution and bidirectionally scaled its activity with reward rate. The other was suppressed during task execution, scaled activity inversely with reward rate and projected to frontal cortex, indicating that claustrocortical outputs produce graded increases in activity with decreasing reward rate. Our results identify the claustrum as a subcortical locus for stable value representations and integrate it into neuronal circuits for value-based decision-making.