Putamen

The putamen is a large subcortical mass of gray matter and an important component of the basal ganglia. Anatomically, it combines with the globus pallidus to form the lentiform nucleus. Functionally, however, the putamen is grouped with the caudate nucleus and nucleus accumbens as part of the striatum, the major input region of basal ganglia circuits.

Cortico-striato-pallido-thalamo-cortical circuits

The putamen participates in cortico-striato-pallido-thalamo-cortical circuits. Its major afferent inputs arise from the cerebral cortex and thalamus, together with important dopaminergic input from the brainstem. There is some functional organization within the putamen: the anterior putamen is more strongly connected with associative cortical regions, whereas the posterior putamen has prominent connections with the primary motor cortex and supplementary motor area. Striatal output is directed mainly toward the pallidal complex and substantia nigra.

Functional correlates

Although traditionally associated with movement, the putamen has broader functions. It contributes to motor control and motor learning, while also participating in cognition, reward, goal-directed behaviour, speech articulation and language-related functions. Thus, the putamen should not be regarded simply as a motor nucleus.

Clinical correlates

The putamen receives blood from perforating branches of the anterior and middle cerebral arteries, particularly the lenticulostriate arteries. Clinically, it is an important site of hypertensive intracerebral hemorrhage and infarction. Dysfunction of putaminal circuits is also important in movement disorders; in Parkinson disease, dopamine depletion particularly affects the posterior putamen.