Basal Ganglia Circuits

Abstract

The basal ganglia circuits have a central role in reward-based action learning, goal-directed behaviors; and habit formation. These processes largely depend on dopamine signals in the striatum, which controls the activity of the other components of the basal ganglia circuits, including the globus pallidus, substantia nigra, and subthalamic nucleus. Reward signals trigger a dopamine peak in the striatum, which promotes selection of a rewarding action and prevents initiation of competing actions. Dopamine also prevents abnormal synchronized oscillatory activity in the basal ganglia circuits. Loss of dopaminergic signaling triggers changes that underlie the motor manifestations of Parkinson disease (PD), including akinesia and levodopa-induced dyskinesia. Imbalance between dopaminergic and cholinergic signaling in the striatum underlies hyperkinetic movement disorders.