Posterior perforated substance
The posterior perforated substance or substantia perforata posterior, is an area of grey matter in the brain situated in the interpeduncular fossa between the cerebral crura.
The posterior perforated substance is a triangular area of grey matter located within the interpeduncular fossa. The apex of the triangle corresponds to the pons, the sides being the cerebral crura and the base forming the ventral, medial aspect of the tegmentum. Its upper part also forms the dorsal part of the floor of the third ventricle.
Blood supply is by numerous small branches of the posterior cerebral arteries.
The posterior perforated substance contains the interpeduncular nucleus.
It derives its name from the gross appearance of the area, appearing to be perforated by many small holes which are actually apertures for the transmission of small branches of the posterior cerebral arteries which go on to supply the thalamus.