Caudate nucleus

The caudate nucleus is a paired, C-shaped mass of subcortical grey matter located deep within each cerebral hemisphere, close to the thalamus and lateral ventricle. It consists of a large anterior head, a body, and a long, thin tail. Together with the putamen, the caudate forms the striatum, which is the major input component of the basal ganglia.

Relationship with the lateral ventricle

The C-shaped course of the caudate nucleus closely follows the lateral ventricle. The head is the enlarged anterior part and forms floor and lateral wall of the frontal horn of lateral ventricle. The body continues posteriorly alongside the body of the ventricle; and the tail curves into the temporal lobe, lying above the temporal horn.

GABAergic neuronal circuitry

Most neurons of the caudate are GABAergic medium spiny neurons, which provide inhibitory outputs to other components of basal ganglia circuits. Smaller populations of cholinergic and GABAergic interneurons are also present.

Neuronal connections and functional correlates

The caudate nucleus receives extensive input from the cerebral cortex, particularly the ipsilateral frontal and prefrontal cortices. Through its basal ganglia connections, it contributes to the planning and selection of voluntary movement, but its functions extend well beyond motor control. It participates in learning, memory, executive function, goal-directed behaviour, motivation and reward-related processing. The anterior caudate nucleus has particularly strong prefrontal connections and is associated with working memory and executive functions, while more posterior regions also participate in learning and visual information processing.

Clinical correlates

Clinically, the caudate nucleus is particularly important in Huntington disease, in which caudate and other striatal neurons undergo progressive degeneration, contributing to motor and cognitive dysfunction. Caudate dysfunction has also been implicated in Parkinson disease and several neuropsychiatric disorders.