[3] Peripaleocortex is formed at borders between isocortex (neocortex) and paleocortex (a subtype of allocortex).
It shows slow histological transition from the three-layered structure characteristic of paleocortex to the typical six-layered structure characteristic of isocortex.
[1] The main peripaleocortex area is anterior insular cortex.
[1] Peripaleocortex does not histologically transit directly to the true isocortex.
One transitional area, which is anatomically located closer to the paleocortex side and histologically, too, more resembling "true" paleocortex, is called peripaleocortex area.