Gray Matter (Meaning and Explanation)

We explain what gray matter is, what its functions are and where it is located. Also, why it is important and what white matter is.

Gray matter - brain — In the brain, gray matter extends to form the cerebral cortex.

What is gray matter?

The element that constitutes certain areas of the central nervous system (brain and spinal cord) of characteristic gray color, composed of neuronal somata (the “body” of neurons) and dendrites lacking myelin, along with glial cells or neuroglia.

The gray matter It is located inside the spinal cord tending towards the center and towards its sides, in the shape of the letter H; and in the brain, however, in the external area except in the basal ganglia, thus forming the cerebral cortex: the most complex nervous structure in the human body.

In principle, since it is not covered with myelin, the gray matter It is not used for the rapid transmission of nerve impulses which is why it is associated with other intellectual capacities of the human being, although it is not possible to affirm that the greater the mass of gray matter, the greater the intelligence, since dolphins have more of it than human beings.

Gray matter function

Gray matter - neurons — Through neuronal connections, gray matter performs mental and cognitive functions.

The gray matter of the brain fulfills the vital function of being the recipient of information and the one in charge of thinking that is, of reasoning and memory in their various areas and meanings. From linguistic ability, perception, interpretation, abstraction and a huge etcetera of mental and cognitive functions, all depend on gray matter and the connections between its multiple types of neurons.

Location of gray matter

The gray matter It is found on the entire brain surface since it makes up the cortex of the brain, the most developed, most complex area with the greatest connections of our entire nervous system. It is also found in the basal ganglia, deep in the cerebellum, and in the areas of the thalamus and hypothalamus.

In turn, It can be found inside the spinal cord in an H-shaped or butterfly-shaped segment, in the dorsal, mediolateral and ventral horns of the spine, as well as in the intermediate area (dorsal nucleus of Clarke).

Importance of gray matter

Medical cases have been seen of people injured in regions of the brain rich in gray matter, and the impact that these injuries can and usually have on various areas of human cognitive functioning has been noted: language capacity, short- or long-term memory. , associative capacity, learning, etc.

Thanks to this, it is known that gray matter is precisely the portion of the nervous system that allowed the emergence of complex thought models creative and abstract in primitive humanity. So it was not enough to have a larger brain to possess human intelligence, but a brain with abundant gray matter and a rough cortex was required, which fosters numerous connections between the neurons that compose it.

Gray matter and white matter

Gray matter differs from white matter in much more than its color, determined by the high presence of myelinated dendrites in the latter (myelin is whitish). They are distinguished in the speed of transmission of nervous information, much faster in white matter than in the gray, and in the depth at which it is found, since the white matter is the interior of the brain (although the covering of the spinal cord).

For a long time it was thought that white matter was passive, but today we know that plays a vital role in the distribution of nervous information and in the modulation of action potentials, that is, it is responsible for basic operational functions that support complex processing, which is responsible for gray matter, especially in the brain.