The basal ganglia are a hub of interconnected nuclei embedded in an extensive brain-wide network, controlling movement, mood states, and higher brain functions. Their selection-suppression operations serve as a paradigm in computational biology and neurorobotics. Basal ganglia dysfunction causes neuropsychiatric disturbances and movement disorders. The basal ganglia are evolutionarily conserved; vertebrate models of basal ganglia disease are translationally valid.