The nucleus reuniens is a region of the thalamic midline nuclear group.

[1][2] In the human brain, it is located in the interthalamic adhesion (massa intermedia).

[5] The nucleus reuniens receives afferent input from a large number of structures, mainly from limbic and limbic-associated structures.

[6] It sends projections to the medial prefrontal cortex, the hippocampus, perirhinal cortex, and entorhinal cortex,[7][8][9] although there exist sparse connections to many other afferent structures as well.

[10] The unique medial prefrontal cortex and hippocampal connectivity allows reuniens to regulate neural traffic in this cortical network related to changes in an organism's attentiveness,[11] making reuniens critical to associative learning,[12] memory retrieval,[13] memory generalization,[14] spatial route planning,[15] and resilience to stress.