The caudate nucleus is a pair of brain structures that make up part of the basal ganglia. It helps control high-level functioning, including:

  • planning movement
  • learning
  • memory
  • reward
  • motivation
  • emotion
  • romantic exchanges

The basal ganglia are neuron cell bodies found deep within the brain involved with movement, behavior, and emotions. This brain circuit receives information from the cerebral cortex, which is a layer of grey matter in the outer brain linked to higher cognitive functions such as information processing and learning. The basal ganglia sends information mainly to the thalamus, which sends information back to the cerebral cortex.

Dysfunction of the caudate nucleus is thought to play a role in many conditions, including:

  • several types of dementia
  • obsessive-compulsive disorder (OCD)
  • attention deficit hyperactivity disorder (ADHD)
  • bipolar disorder
  • schizophrenia
  • Huntington’s disease
  • Parkinson’s disease
  • autism
  • Tourette syndrome

One caudate nucleus is located deep inside each of the brain’s two hemispheres, near the thalamus. The nuclei feature a wide head that tapers into a body and a thin tail. They are curved and resemble the letter “C” in shape.

The caudate nucleus helps process visual information and control movement. It’s involved in working memory, cognitive function, and emotions.

The structure plays a vital role in how the brain learns, specifically the storing and processing of memories. As a feedback processor, it uses information from past experiences to influence future actions and decisions.

This is important to the development and use of language. Experts think that communication skills are controlled mostly by the caudate nucleus and the thalamus.

Another brain structure called the substantia nigra releases dopamine that projects to the caudate nucleus. This is required for the proper functioning of the basal ganglia system. The substantia nigra, which controls movement, is connected to the caudate nucleus and is also part of the basal ganglia.

Some brain specialists suspect variations in the caudate nucleus may play a role in the development of several neurological and psychiatric disorders.

Dopamine dysfunction has been linked to Parkinson’s disease and other movement disorders. People with Parkinson’s disease have low levels of dopamine, mostly due to the impairment of neurons in the substantia nigra.

A 2019 study found that nearly half of people in the early stages of Parkinson’s disease have signs of neurodegeneration in the caudate nucleus. Early involvement of the caudate nucleus was found to result in worse outcomes over 4 years of follow-up, including cognitive impairment, depression, and movement problems.

Lesions in the caudate nucleus can also result in abulia, also known as apathy or lack of will. Abulia is thought to be linked to problems with parts of your brain that depend on dopamine to send messages. It’s a common symptom in people with:

  • Parkinson’s disease
  • dementia
  • Alzheimer’s disease

Damage to the caudate nucleus may also be involved in:

  • OCD
  • ADHD
  • Tourette syndrome
  • autism