The putamen is a round structure located at the base of the forebrain (telencephalon). The putamen and caudate nucleus together form the dorsal striatum. It is also one of the structures that comprises the basal ganglia. Through various pathways, the putamen is connected to the substantia nigra and globus pallidus. The main function of the putamen is to regulate movements and influence various types of learning. It employs dopamine to perform its functions. The putamen also plays a role in degenerative neurological disorders, such as Parkinson’s disease.
The putamen is a structure in the forebrain. Along with the caudate nucleus it forms the dorsal striatum. The caudate and putamen contain the same types of neurons and circuits – many neuroanatomists consider the dorsal striatum to be a single structure, divided into two parts by a large fiber tract, the internal capsule, passing through the middle. The putamen, together with the globus pallidus, makes up the lenticular nucleus. The putamen is the outer most portion of the basal ganglia. These are a group of nuclei in the brain that are interconnected with the cerebral cortex, thalamus, and brain stem. The other parts of the basal ganglia include the dorsal striatum, substantia nigra, nucleus accumbens, and the subthalamic nucleus.
In mammals, the basal ganglia are associated with motor control, cognition, emotions, and learning. The basal ganglia are located on the left and right sides of the brain, and have rostral and caudal divisions. The putamen is located in the rostral division as part of the striatum. The basal ganglia receive input from the cerebral cortex, via the striatum.
After discovering the function of the putamen, it has become apparent to neurologists that the putamen and basal ganglia play an important role in Parkinson’s disease and other diseases that involve the degeneration of neurons.
Parkinson’s diseases is the slow and steady loss of dopaminergic neurons in substantia nigra pars compacta. In Parkinson’s disease the putamen plays a key role because its inputs and outputs are interconnected to the substantia nigra and the globus pallidus. In Parkinson’s diseases the activity in direct pathways to interior globus pallidus decreases and activity in indirect pathways to external globus pallidus increases. Together these actions cause excessive inhibition of the thalamus. This is why Parkinson’s patients have tremors and have trouble performing voluntary movements. It has also been noted that Parkinson’s patients have a difficult time with motor planning. They must think about everything they do and cannot perform instinctive tasks without focusing on what they are doing.
Other diseases and disorders
The following diseases and disorders are linked with the putamen:
Cognitive decline in Alzheimer’s disease
Dementia with Lewy bodies
Attention Deficit Hyperactivity Disorder
Other anxiety disorders