Ventral anterior nucleus

The ventral anterior nucleus of the thalamus (VA) is a motor relay nucleus located at the anterior part of the ventral tier of the lateral thalamic nuclear group.

Basal ganglia thalamocortical motor circuits

The ventral anterior nucleus is functionally associated with the basal ganglia–thalamocortical motor circuit. It receives predominantly inhibitory motor-related input from the internal segment of the globus pallidus and the substantia nigra pars reticulata, and relays this information mainly to premotor and supplementary motor areas of the cerebral cortex.

Functional correlates

Through the basal ganglia thalamocortical neuronal connectivity, the ventral anterior nucleus modulates the cortical activity, thus contributing particularly to the planning, preparation and initiation of voluntary movement, rather than directly generating movement. This motor role should be distinguished from that of the adjacent ventral lateral nucleus, which has particularly important cerebellar as well as basal-ganglia-related motor connections.