which link the sub-divisions of the PFC with the striatum, pallidum, substantia nigra pars reticulata, subthalamic nucleus, thalamus, and back to the frontal cortex.[2] The FSCs of relevance to neuropsychiatric disorders involve the three segregated circuits originating from the dorsolateral prefrontal, orbitofrontal, and anterior cingulate cortices, respectively, and involving corresponding regions of the subcortical regions mentioned above. Each of these three circuits is intrinsically organized by way of direct and indirect pathways [Figure 1]. Further, each of these pathways has open connections with other brain structures including the limbic, midbrain as well as diencephalic structures.
