Cortical-Subcortical Loop

Synonyms

Basal ganglia-thalamocortical circuit; Cortico-basal ganglia loop

Definition

The cortical-subcortical loop describes a class of distinct, parallel circuits that connect specific regions of cerebral cortex with the basal ganglia and specific thalamic nuclei. The thalamic nuclei complete the loop by projecting back to the same regions of cortex from which the circuits originate.

Current Knowledge

Several distinct, anatomically segregated cortical-subcortical loops may be characterized based on the functional role of the cortical regions involved.

Motor Loop

The motor loop plays a role in the preparation and execution of movement. Primary motor cortex and associated premotor areas project via the putamen to the ventral tier nuclei of the thalamus, which then complete the loop with projections back to motor cortex. Somatotopic organization is maintained through all stages of this circuit.

Oculomotor Loop

The oculomotor loop is involved in the control of eye movements. The frontal...