Five parallel anatomic circuits link regions of the frontal cortex to
the striatum, globus pallidus/substantia nigra, and thalamus. The circuits
originate in the supplementary motor area, frontal eye fields, dorsolateral
prefrontal region, lateral orbito-frontal area, and anterior cingulate
cortex. Open loop structures that provide input to or receive output from
specific circuits share functions, cytoarchitectural features, and
phylogenetic histories with the relevant circuits. The circuits mediate
motor and oculomotor function as well as executive functions, socially
responsive behavior, and motivation. Neuropsychiatric disorders of
frontal-subcortical circuits include impaired executive function,
disinhibition, and apathy; indicative mood disorders include depression,
mania, and lability. Transmitters, modulators, receptor subtypes, and
second messengers within the circuits provide a chemoarchitecture that can
inform pharmacotherapy.Abstract Teaser