Habenular trigone

The habenular trigone is a small triangular elevation of the epithalamus, located at the posteromedial aspect of the thalamus, adjacent to the third ventricle and close to the pineal gland. It is produced by the underlying habenular nuclei and therefore marks the surface location of the habenular complex.

Anteriorly, the habenular trigone is continuous with the stria medullaris thalami, which carries afferent fibres to the habenular nuclei. Posteromedially, the habenular regions of the two sides are interconnected by the habenular commissure, which is closely related to the superior part of the pineal stalk.