The reticular nucleus of the thalamus is a thin, sheet-like structure along the lateral aspect of the thalamus just medial to the posterior limb of the internal capsule (eFig. 9.30). Unlike the rest of the thalamic nuclei, the reticular nucleus does not send projections to the cerebral cortex, but rather receives input from other thalamic nuclei and the cortex, which project back to the thalamus. Functionally, this organization of inputs and outputs, along with the GABAergic neurons of the reticular nucleus, allows it to regulate thalamic activity quite effectively.