Architectonic structure of the orbital and medial prefrontal cortex

The chapter describes the structural organization of the orbital cortex (OFC), together with the medial prefrontal cortex. It reviews previous areal maps of this cortex, and provides a description of architectonic divisions of the cortex based on analysis of eight staining methods in nonhuman primates and humans. Twenty-two areas were recognized, most of which are subdivisions of previously described areas. Distinct subregions were found ranging from several agranular insular areas in the posterior orbital region, through a dysgranular zone in the central region (subdivisions of area 12 and 13), to a granular region in more rostral portions of cortex (subdivisions of areas 10 and 11). The comparable regions in humans are presented with reference to stereotaxic space. An analysis of the comparable regions in rodents is also provided.