Thalamic projections sustain prefrontal activity during working memory maintenance

Using pathway-specific optogenetic inhibition, the authors demonstrate that projections from the mediodorsal thalamus to prefrontal cortex support the maintenance of working memory, while prefrontal–thalamic projections support subsequent choice selection. Thalamo–prefrontal projections have a circuit-specific role in sustaining prefrontal delay-period activity, a neuronal signature required for successful task performance.