Neural soma or perikaryon: parts and functions

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. carried out, both voluntarily and involuntarily, and whether we refer to physical behaviors or to cognitive processes or emotional

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 perikaryon, to which this article is dedicated.

• Related article: "Types of neurons: characteristics and functions"

The central part of the neuron: The soma or perikaryon

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

The bodies of neurons make up what we call gray matter, linked to the processing of nervous information. In fact, different brain structures of great importance are mainly made up of gray matter, such as the cortex itself, the basal ganglia, the thalamus or the hypothalamus.

• You may be interested: "Gray matter of the brain: structure and functions"

Main parts of the neuronal soma

Within the soma or perikaryon we can find a large number of elements, all of them of great importance, that participate in the proper functioning 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 instructions are genetics that govern the formation, growth, functioning and death of the neuron, that is, the DNA. Within or around the core can be found the nucleolus, which generates RNA transcription that will end up generating the ribosomes present in the cell.

• Related article: "Differences between DNA and RNA"

2. Cytoplasm

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

3. Cytoskeleton

This item made up of different types of filaments and tubules They contribute to providing structure and shape to the perikaryon and also participate in the migration and movement of the different components of the soma.

4. Nissl's bodies

Rough endoplasmic reticulum clusters present mainly in the soma (although they can also be observed in the dendrites) and that contain a large number of ribosomes, which are involved in the creation of proteins and neurotransmitters. In addition, they are a fundamental part of the perikaryon, since if the cell is damaged (not only in the soma but also for example in the axon) they 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

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

6. Smooth endoplasmic reticulum

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

7. Lysosomes

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

8. Ribosomes

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

9. Mitochondria

Fundamental elements of the cell whose main function is to give it energy and keep it alive, carrying out cellular respiration and synthesizing ATP (an element that cells use as fuel).

Its function

The soma or pericarion plays a fundamental role: it is about the part of the neuron that governs the functioning and keeps this biological unit alive, finding the nucleus of the cell (in which the genetic instructions present in the DNA are found) in it. It is responsible for producing and maintaining sufficient energy level so that the cell can continue to function. It also contains elements that make up the cell's cytoskeleton, as well as some elements that repair it from possible damage, such as Nissl 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 are going to be part or will initiate the synthesis of most neurotransmitters.

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

It is the part of the neuron that, likewise, allows the processing of nervous information and your reaction to it, being the somas of the neurons an important part when it comes to explaining how human beings function and govern their behavior.

Bibliographic references

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