The term area 12l (macaque) refers to a portion of the orbital gyri defined on the basis of internal structure in the macaque. It is one of four components of area 12 in the orbitomedial prefrontal cortex. The other components are area 12r (macaque), area 12m (macaque), and area 12o (macaque). An identifying feature of area 12l is a band of cells in the external granular layer (II) that stain for 8b3 antibody to chondroitin sulfate proteoglycan. Other distinguishing features are large vertical fiber bundles and moderately dense horizontal fiber bundles revealed by myelin stain in the internal granular layer (IV) and internal pyramidal layer (V) ( Carmichael-1994 ). Some authors divide area 12 into only two parts, an orbital part and a lateral part ( Paxinos-2009a ). Its human equivalent is area 47/12l ( Ongur-2003 ). As granular prefrontal cortex, it has no equivalent in the rat ( Wallis-2012 ).