The term area 10o refers to a portion of the orbital gyri at the frontal pole that is defined on the basis of internal structure in the macaque. It is one of two components of rostral orbital cortex. The other component is area 11. A significant feature of area 10o is the presence of radial striations revealed by Nissl stain in the external pyramidal layer (III), the internal granular layer and the internal pyramidal layer (V) ( Carmichael-1994 ). In Paxinos-2009a it is named '10V', Its human equivalent is the orbital part of area 10p ( Ongur-2003 ). As granular prefrontal cortex, it has no equivalent in the rat ( Wallis-2012 ).