Caudate nucleus: characteristics, functions and disorders

When we think of the brain, we usually imagine the superficial and outermost layer, the cerebral cortex. However, underneath this we can find a large number of structures of fundamental importance for the survival of the human being, all of them participating in different types of functions such as the integration of information.

One of these subcortical structures is the caudate nucleus, whose characteristics we will see below.

• Related article: "Parts of the human brain (and functions)"

What is the caudate nucleus?

The caudate nucleus is a subcortical structure, that is, located inside the brain, which is part of the basal ganglia. Together with the putamen and the nucleus accumbens, it forms the so-called striatum, an element closely linked to movement control.

Located above the thalamus and below the orbitofrontal cortex to later curve towards the occipital lobe, the caudate nucleus connects both with the rest of the basal ganglia and with the frontal cortex and the limbic system. We have two units of this nucleus, each one located in a cerebral hemisphere. At the neurotransmitter level, the caudate nucleus is mainly influenced by dopamine and

GABA.

The caudate nucleus is usually divided into three parts, the head, the body and the tail. While the first is one of the thickest parts and is in more contact with the frontal cortex, the tail is connected to the limbic system. Head and body are in close contact with the lateral ventricles.

• You may be interested: "Basal ganglia: anatomy and functions"

Main functions of the caudate nucleus

The caudate nucleus and the set of basal ganglia are highly important in the human nervous system, participating in essential functions for guarantee both a correct adaptation to the environment and survival itself by allowing the regulation of behavior through aspects such as memory and motivation. In addition, they have also been largely linked to performance and coordination of movements.

Below you can find detailed some of the functions that have been attributed to the caudate nucleus.

1. Movement control

Along with the rest of the basal ganglia, the caudate nucleus has traditionally been considered to have a high participation in motor control and coordination. The maintenance of the position of the limbs of the body, and the precision in the fine movement are some of the aspects in which the caudate participates. This can be seen in the consequences of its dysfunction, in disorders such as Parkinson's and Huntington's chorea.

2. Memory and learning

Learning and memory are elements in which the caudate nucleus has also been found to play an important role. For example, procedural learning depends on this brain area. Specifically, the caudate nucleus allows the organism to be able to obtain feedback from the outside world regarding what is happening and what is being done. It also participates in the understanding of auditory stimuli, such as those of language.

3. Feeling of alarm

Another of the main functions of this brain region is the perception of the sense of alarm, thanks to which we can identify that something is not working correctly and respond accordingly.

4. Motivation

The caudate nucleus is of paramount importance with regard to the motivational capacity of the human being. It is a structure that connects the limbic system with the frontal cortex, so that cognitive information is transformed and linked to an emotional meaning. Its destruction can generate the appearance of extreme apathy and PAP syndrome.

Disorders and disorders in which it participates

The caudate nucleus and the basal ganglia in general, due to its multiple connections with other brain areas such as the cortex orbitofrontal or limbic system, are structures of great importance for the correct functioning of the nervous system and for our adaptation to the half.

The presence of alterations can generate or participate in the genesis or maintenance of various types of disorder. Some of the disorders in which the caudate nucleus participates are as follows.

1. Obsessive-Compulsive Disorder and Other Obsessive Disorders

As we have mentioned, the caudate nucleus plays an important role in the response mechanism to a specific situation, as well as in the sense of alarm. In the TOCthis mechanism presents an over-activation, finding that patients with this disorder tend to have high neural activation in the caudate.

In addition to OCD itself, in other disorders of a similar nature such as hoarding disorder, excoriation disorder or trichotillomania can also be found this high level of activity.

2. Attention Deficit Hyperactivity Disorder

ADHD is another disorder in which the caudate nucleus has a certain level of involvement. Specifically, in this case an activation is observed below the usual, with which the ability to recall, feedback and motivation are reduced.

• Related article: "Attention Deficit Hyperactivity Disorder (ADHD), also in adults"

3. Huntington's chorea

In Huntington's chorea, the caudate nucleus is one of the first areas to present neuronal death, and in the long run it ends up generating a progressive loss of executive and memory functions and performing uncontrolled movements in the form of twists and turns of the body parts similar to a dance.

4. Parkinson's

Parkinson's is another of the diseases linked to the caudate nucleus. Specifically, parkinsonian symptoms are produced by the degradation and death of neurons that form the nigrostriatal pathway.

5. Loss of psychic self-activation syndrome

Damage to the caudate nucleus causes loss of motivation and makes the connection between emotion and cognition difficult. That is why its destruction generates a deep sense of indifference whatever happens, even if it threatens your very survival.

6. Hypermnesia

While it is generally not considered a disorder, the presence of hypermnesia in some people it has been linked, among other brain regions, with the caudate nucleus. Specifically, it has been observed that people with above average memory abilities they have a larger caudate nucleus than most people.

Bibliographic references:

• Carlson, N.R. (2014). Physiology of Behavior (11 Edition). Madrid: Pearson Education.

• Kandel, E.R.; Schwartz, J.H. & Jessell, T.M. (2001). Principles of neuroscience. Fourth edition. McGraw-Hill Interamericana. Madrid.

• Melnick, M.E. (2013). Basal ganglia disorders. In: Umphred DA, Burton GU, Lazaro RT, Roller ML, eds. Umphred's Neurological Rehabilitation. 6th ed. Philadelphia, PA: Elsevier Mosby; chap 20.

• Packard, M.G. & Knowlton, B.J. (2002). Learning and memory functions of the basal ganglia. Annu Rev Neurosci 25: 563-59.