Ventral lateral nuclei

The ventral lateral thalamic nucleus (VL) is a motor relay nucleus located in the ventral tier of the lateral nuclear group of the thalamus. It lies posterior to the ventral anterior (VA) nucleus and anterior to the ventral posterior nuclear complex.

Cerebellar and basal ganglia connections

• The ventral lateral nucleus receives major motor-related input from the cerebellum, particularly from the deep cerebellar nuclei, with cerebellothalamic fibres reaching the thalamus mainly via the superior cerebellar peduncle.

• The VL nucleus also receives basal-ganglia-related inputs.

• Its efferent fibres project predominantly to the primary motor and premotor areas of the cerebral cortex, forming an important component of thalamocortical motor circuitry.

Functional correlates

Functionally, the ventral lateral nucleus contributes to the coordination, scaling and execution of voluntary movement, particularly by relaying cerebellar information concerned with the timing and coordination of motor activity to the cerebral cortex. It therefore forms an important link in the cerebello-thalamo-cortical motor pathway.

The VL nucleus should also be distinguished from the more anterior ventral anterior nucleus, which is more strongly associated with basal ganglia motor loops and motor planning.

Clinical correlates

Clinically, disruption of thalamic motor circuitry may contribute to abnormalities of movement, while motor regions of the ventral thalamus, including the ventral intermediate region, are important targets for deep brain stimulation in selected tremor disorders.