Neurons are one of the most important cell types in our body , since they allow the transmission of information between its different parts through the nervous system. Through them, a series of bioelectric impulses are generated and transmitted that allow us to carry out each of the actions that we carry out, both voluntarily and involuntarily, and whether we are referring to physical behaviour or cognitive or emotional processes.

But neurons are not homogeneous masses: if we focus on their structure we can distinguish different elements or parts. One of the most important is the soma of the neuron, or pericarion , to which this article is dedicated.

The central part of the neuron: the soma or pericaryous

The central and most important element of the cell is known as soma or pericharion, in which the nucleus is found and from which its other parts are derived, as extensions of the first: dendrites and axon. The shape of the soma, as well as its position in relation to the rest of its components in the same neuron, can vary greatly depending on the type of neuron we are talking about (although it is usually rounded and large).

The somas of the neurons form what we call grey matter , linked to the processing of nervous information. In fact, different brain structures of great importance are mainly formed by grey matter, such as the cortex itself, the basal ganglia, the thalamus or the hypothalamus.

Main parts of the neuronal soma

Within the soma or pericarion we can find a great amount of elements, all of them of great importance, that participate in the good operation of the cell and in its maintenance. The main ones among them are the following.

1. Core

The main and most important element of the soma is the nucleus, in which the genetic instructions governing the formation, growth, functioning and death of the neuron, i.e. the DNA, are contained. Within the nucleus or around it, the nucleolus can be found , which generates the RNA transcription that will end up generating the ribosomes present in the cell.

2. Cytoplasm

The cytoplasm is the liquid medium in which the nucleus and the rest of the elements of the soma are found, participating actively in the cellular metabolism and the facilitation of its movement . It is limited by the cytoskeleton, the membrane of the neuron.

.

3. Cytoskeleton

This element formed by different types of filaments and tubules contribute to give a structure and shape to the pericarion and also participate in the migration and movement of the different components of the soma.

4. Nissl bodies

Clusters of rugged endoplasmic reticulum present mainly in the soma (although they can also be seen in dendrites) and containing a large number of ribosomes, which participate in the creation of proteins and neurotransmitters. They are also a fundamental part of the pericarion, since if the cell is damaged (not only in the soma but also, for example, in the axon) it will be these elements that contribute to its regeneration, dissolving and sacrificing themselves to maintain the functioning of the neuron (in a process known as chromatolysis).

5. Golgi apparatus

An element of great importance for the functioning of the neuron, the Golgi apparatus is a large organelle in which the proteins generated by the Nissl bodies are temporarily stored, incorporating other elements in such a way that they can be packaged into macromolecules that can be sent through the neuron to the nerve terminals.

6. Smooth endoplasmic reticulum

Network of interconnected tubules whose main function is to serve as an assembly point for many substances secreted by the other elements . It also participates in the synthesis of lipids and elements related to the membrane of the neuron. The Golgi apparatus mentioned above is, in fact, a smooth endoplasmic reticulum.

7. Lysosomes

Set of elements present in the cytoplasm whose main function is to degrade the intracellular material , facilitating the functioning of the soma by eliminating harmful residues.

8. Ribosomes

Present in some of the above structures but also freely locatable in the cytoplasm, ribosomes are macromolecules formed by ribosomal RNA and some proteins that are responsible for protein synthesis. Technically, they are the elements that carry out the expression of the genetic information present in the nucleus, through this synthesis.

9. Mitochondria

Fundamental elements of the cell whose main function is to provide it with energy and keep it alive , carrying out cellular respiration and synthesizing ATP (element used by cells as fuel).

Its function

The soma or pericarion plays a fundamental role: it is the part of the neuron that governs the functioning and keeps this biological unit alive , the nucleus of the cell (in which the genetic instructions present in the DNA are found) being found in it. It is in charge of producing and maintaining the level of energy sufficient for the cell to continue to function. It also contains elements that form the cell’s cytoskeleton, as well as some elements that repair it from possible damage, such as Nissl’s bodies.

Perhaps the most important role of the soma is the fact that it carries out the synthesis of most of the proteins found in the neuron, and among them those that will be part of it or will initiate the synthesis of most of the neurotransmitters .

Finally, it is from it that the extensions that will receive and send the nervous information are derived.

This is the part of the neuron that, likewise, allows the processing of the nervous information and its reaction to it , being the somas of the neurons an important part in explaining how human beings function and govern their behaviour.

Bibliographic references

  • Kandel, E.R.; Schwartz, J.H. & Jessell, T.M. (2001). Principles of neuroscience. Fourth edition. McGraw-Hill Interamerican. Madrid.
  • Ramón y Cajal, S. (2007). Histology of the nervous system of man and vertebrates. Volume i. Ministry of Health and Consumer Affairs. Madrid.