The term lateral agranular insular region refers to a component of the orbitomedial prefrontal cortex (macaque). One of two subdivisions of agranular orbitofrontal cortex, it is differentiated from the other subdivision, the medial agranular insular region, by its distinct lamination into five layers with sublamination of the internal pyramidal layer (V). It has three components: area Ial (macaque), area Iapl (macaque) and area Iai (macaque) ( Carmichael-1994 ). The human has equivalent areas: area Iai and area Ial, and may have an area Iapl (see area Iapl (macaque) ( Ongur-2003 ). As a component of insulo-orbital cortex, its equivalent in the rat and mouse would be in the agranular insular cortex.