Medial prefrontal cortices are unified by common connections with superiortemporal cortices and distinguished by input from memory-related areas in the rhesus monkey

Medial prefrontal cortices in primates have been associated with emotion, m emory, and complex cognitive processes. Here we investigated whether the pa ttern of cortical connections could indicate whether the medial prefrontal cortex constitutes a homogeneous region, or if it can be parceled into dist inct sectors. Projections from medial temporal memory-related cortices subd ivided medial cortices into different sectors, by targeting preferentially caudal medial areas (area 24, caudal 32 and 25), to a lesser extent rostral medial areas (rostral area 32, areas 14 and 10), and sparsely area 9. Area 9 was distinguished by its strong connections with premotor cortices. Proj ections from unimodal sensory cortices reached preferentially specific medi al cortices, including a projection from visual cortices to area 32/24, fro m somatosensory cortices to area 9, and from olfactory cortices to area 14. Medial cortices were robustly interconnected, suggesting that local circui ts are important in the neural processing in this region. Medial prefrontal cortices were unified by bidirectional connections with superior temporal cortices, including auditory areas. Auditory pathways may have a role in th e specialization of medial prefrontal cortices in species-specific communic ation in non-human primates and language functions in humans. (C) 1999 Wile y-Liss, Inc.