The basal ganglia are a series of parts of the brain located deep within the brain that are important for performing various functions. They are a collection of various structures and substructures, which can be grouped according to their connections with each other.

One of these structures, or rather a group of them, is the so-called lenticular nucleus , which is especially relevant in motor management, as well as in learning and motivation.

The lenticular nucleus: parts and characteristics

The lenticular nucleus is a subcortical structure of the brain, located on the inside of the brain. This nucleus is part of the basal ganglia, a set of structures configured by gray matter (i.e., it is mainly somas and dendrites).

Also called extraventricular nucleus of the striated body , the lenticular nucleus is configured by three segments, although these three segments can be divided mainly into two structures; putamen (which would be the outermost segment) and globus pallidus (which would collect the middle and inner segments).

Thus, the lenticular nucleus can be considered to be the union of two other structures characteristic of the basal ganglia, putamen and globus pallidus .

This cuneiform structure is in contact with the internal capsule, which separates it from the thalamus and the caudate, and with the external capsule, which separates it from the cloister and the insula. It is connected to the aforementioned thalamus, the cerebral cortex and the set of structures that make up the brain stem.

Functions associated with this subcortical structure

The lenticular nucleus, like the set of structures that make up the basal ganglia, is a structure or set of structures of great importance for the correct functioning of the human being’s life. Specifically, it has been observed to be of great importance in the following areas.

Motor skills

One of the aspects in which more research has been carried out and which has been known for longer is the great importance of the lenticular nucleus in motility and movement management and coordination . Its main task in this sense is the adaptation of the movement to the situations that are being experienced and the adjustment to the situational demands.

Maintenance of posture

The lenticular nucleus participates not only in the performance of specific movements, but also has to do with the maintenance of posture. Damage to the lenticular nucleus can generate difficulties in walking , lack of coordination or uncontrollable trembling.

Automation of movements

The automation of movements is also affected by the lenticular nucleus, allowing it to become accustomed to its performance.

Learning

The lenticular nucleus influences the learning processes . Specifically, it helps to generate procedural learning. Furthermore, through its various connections the lenticular nucleus contributes to the creation of categories when organising and structuring the world.

Motivation

Like other areas such as the caudate nucleus, the lenticular nucleus also contributes greatly in linking the rational with the emotional , allowing both types of information to be integrated. This means that thanks to its connections we can link a knowledge or stimulus to an emotion, which can either motivate or de-motivate us.

Disorders linked to the lenticular nucleus

The presence of alterations and lesions in the basal ganglia can have a devastating impact on the health of the body, as well as diminish its most basic capabilities. Some of the alterations that are linked to damage to the lenticular nucleus are the following.

Subcortical dementias

The progressive degeneration caused by this type of dementia tends to start in different subcortical structures, one of the most frequent being the basal ganglia. The dementias produced by Parkinson’s or Huntington’s Chorea are two of the most well known, which involve an uncoordinated gait, the performance of different spasmodic movements either at rest or during the performance of movements and a loss of memory and executive abilities.

Psychomotor disorders

Disorders such as tics or Gilles de la Tourette’s, or Parkinson’s disease itself without necessarily causing dementia, are also influenced by altered basal ganglia.

Obsessive-compulsive disorder

OCD has also been linked in part to overactivation of the basal ganglia, especially the caudate nucleus and putamen (the latter forming part of the lenticular nucleus).

ADHD

ADHD is another disorder that is influenced by the presence of damage to the lenticular nucleus, making it difficult to maintain motivation and promoting the appearance of tics and agitation.

Bibliographic references:

  • Carlson, N.R. (2014). Physiology of Behavior (11th Edition). Madrid: Pearson Educación.
  • Kandel, E.R.; Schwartz, J.H. & Jessell, T.M. (2001). Principles of neuroscience. Fourth edition. McGraw-Hill Interamerican. Madrid.