Gray matter of the brain: structure and functions

The somas of neurons make up this substance of the nervous system.

Almost all of us have heard at some time or another about the gray matter that one person or another has. In Spain it is a concept that has been popularly associated with intelligence, but in reality its role is much more important than that.

Gray matter can be found in the brain, yes, and its existence has to do with intelligence.And its existence has to do with the way in which mental processes related, among other things, to cognition and intelligence are developed. But having more or less gray matter does not imply being more or less intelligent. This is because its function is more general and essential, and has to do with the basic functioning of the nervous system.

What is gray matter?

Gray matter, also called gray matter, comprises the areas of the central nervous system in which the somas of neurons predominate (i.e., the part of the neuron in which its nucleus and its "body" from which the branches depart). (i.e., the part of the neuron in which its nucleus is located and its "body" from which the branches depart).

The gray color of these areas contrasts with the white color of the rest of the nervous system, which has this appearance because the axons of the neurons predominate in these areas, i.e., the prolongations that arise from the somas and are covered by myelin, which are white in color.

In qualitative terms, there are no relevant differences between the composition of the white matter and that of the gray matter: in both there are neuronal somas, dendrites and axons with myelin. However, there are significant there are significant differences in the quantities and proportions in which these elements are present in each of them..

Thus, technically, gray matter is not a part of the brain, but the material from which some parts of the brain are constructed.

The distribution of gray matter

The areas of the brain and spinal cord that are made up of gray matter do not form a homogeneous whole, but are distributed and in some cases there is white matter between them. However, in most cases these areas are sufficiently extensive to be easily distinguished with the naked eye.

In the medulla, the gray matter is found in the central and lateral part of the medulla. (in any of its sections, regardless of the height at which it is), but in the cerebrum it is more widely distributed.

The cerebral cortex, for example, is made up of gray matter.The same is true for the basal ganglia, which are located below, the deepest and the most superficial part of the cerebellum and many other scattered areas, such as the thalamus and the hypothalamus.

The function of these areas

Unlike what the white matter does, in which myelin causes nerve impulses to be transmitted rapidly along the axons, the gray matter cannot make the information flowing through it go as fast. The main function of these areas is not to make the electricity pass through them quicklyThe main function of these zones is not to make electricity pass through them quickly, but to process information, whatever it may be.

As the content of the information processed by the gray matter areas is very diverse, the effects of a decrease or an increase of this substance are also varied. That is why lesions in these areas depend on the type of structure they affect. However, no part of the gray matter can work without the help of the white matter, as they need to be connected to each other to function properly.

As for the gray matter of the spinal cord, it is in charge of acting as an information directory.In other words, it is where it is decided which information enters and exits to the nerves of the peripheral nervous system and which information should travel up or down the spinal cord. In addition, there are some theories about memory according to which memories are stored chemically within the neuronal somas, which are much more abundant in this type of brain tissue.

Concluding

The presence of gray matter indicates that the part of the brain in which it is located receives information from many areas of white matter and that, in some way, they function as clusters of white matter processing, function as information processing clusters and in which the nerve impulses that travel along the axons meet a relay that directs them to another destination.

This implies, among other things, that the gray matter and the white matter need each other to work as they should; not for nothing are they two types of brain tissue differentiated by the concentration of the part of the neurons that predominate most in them (axons or somas), and these small nerve cells form an organic unit that cannot be separated without destroying it.