The term medial agranular insular region refers to a component of the orbitomedial prefrontal cortex (macaque). It is defined on the basis of multiple architectonic features. One of two subdivisions of the agranular orbitofrontal cortex, it is differentiated from the other subdivision, the lateral agranular insular region, by its indistinct lamination, particularly by absence of sublamination of the internal pyramidal layer (V). The medial region is in turn subdivided into two areas: area Iam (macaque) and area Iapm (macaque) ( Carmichael-1994 ). The human has equivalent areas: area Iam and area Iapm ( Ongur-2003 ). As a component of insulo-orbital cortex, its equivalent in the rat and mouse would be in the agranular insular cortex.