Posterior perforated substance

The posterior perforated substance is located in the depressed area between the cerebral crura (termed interpeduncular fossa), and consists of a layer of gray matter which is pierced by small apertures for the transmission of blood vessels (branches of cerebral posterior artery: posteromedial central arteries and thalamoperforating arteries)

The lower part of the posterior perforated substance lies on the ventral aspect of the medial portions of the tegmenta, and contains the interpeduncular nucleus.

Its upper part assists in forming the floor of the third ventricle.