The reuniens nucleus is among the largest of the midline thalamic nuclei, extends throughout the rostral-caudal portion of the thalamus, and is connected to the hippocampus and medial prefrontal cortex. Afferents to the reuniens nucleus include the dorsal-ventral medial prefrontal cortex (all four subregions), subiculum, cortex, basal forebrain, diencephalon, brainstem. The reuniens nucleus then projects to the CA1 and subiculum of the hippocampus as well as the prelimbic, infralimbic, and anterior cingulate cortex subregions of the medial prefrontal cortex. Many projection neurons of the reuniens nucleus glutamatergic. It is involved with working memory.