Basal Ganglia

The basal ganglia are a set of deep gray matter nuclei consisting of the striatum (caudate and putamen), globus pallidus (internal and external segments), subthalamic nucleus, and substantia nigra. They receive inputs from nearly every cortical area and send output back to the cortex via the thalamus through parallel but anatomically segregated circuits. Historically, the basal ganglia were mainly seen as structures for regulating voluntary movement. Since the mid-1990s, however, the basal ganglia, with their rich connections to the cortex by networks known as frontal-subcortical circuits, have become increasingly appreciated as being important for regulation of higher order cerebral processes that control cognition, behavior, and personality. This entry reviews the parallel yet separate frontal-subcortical circuits and their associated roles in regulation of motor, cognitive, and ...