FRONTAL-SUBCORTICAL CIRCUITS AND NEUROPSYCHIATRIC DISORDERS

Five parallel anatomic circuits link regions of the frontal cortex to the striatum, globus pallidus/substantia nigra, and thalamus. The circ uits originate in the supplmentary motor area, frontal eye fields, dor solateral prefrontal region, lateral orbitofrontal area, and anterior cingulate cortex. Open loop structures that provide input to or receiv e output from specific circuits share functions, cytoarchitectural fea tures, and phylogenetic histories with the relevant circuits. The circ uits mediate motor and oculomotor function as well as executive functi ons, socially responsive behavior, and motivation. Neuropsychiatric di sorders of frontal-subcortical circuits include impaired executive fun ction, disinhibition, and apathy; indicative mood disorders include de pression, mania, and lability. Transmitters, modulators, receptor subt ypes, and second messengers within the circuits provide a chemoarchite cture that can inform pharmacotherapy.