Anterior perforated substance

The anterior perforated substance is an irregularly quadrilateral area in front of the optic tract and behind the olfactory trigone, from which it is separated by the fissure prima; medially and in front, it is continuous with the subcallosal gyrus; it is bounded laterally by the lateral stria of the olfactory tract and is continued into the uncus.

Its gray substance is confluent above with that of the corpus striatum, and is perforated anteriorly by numerous small blood vessels that supply such areas as the internal capsule.