Reticular Formation: Characteristics, Functions And Associated Diseases
A good part of the brain’s structures can be easily located and separated from the rest. However, there are others that, being more distributed throughout various parts of the brain, are more difficult to detect.
The reticular formation is one of these, although the fact that it is more discreet does not mean that it is less important. In fact, we need it to live and be aware of what happens to us.
Below we will see the characteristics of the reticular formation, its functions and the problems that may appear if something interferes with its state due to diseases or injuries.
The reticular formation is a network of neurons found between the brain stem and the diencephalon, specifically the thalamus. That is, it is located in one of the lowest parts of the brain, and therefore has a fundamental role in everything that happens in the higher areas.
As the reticular formation is a network of neurons, its limits and borders are diffuse, and it is not easy to know where it begins and where it ends. For example, with the naked eye it is practically impossible to locate it, and in any case it is possible to roughly see the structures through which it is distributed.
It is considered that the “starting point” of the reticular formation is a part of the brain stem called the annular pons, between the medulla oblongata and the midbrain, and that from there it rises until it reaches the thalamus, opening more and more, like a fan. This formation is made up of a hundred groups of neurons scattered irregularly throughout the nervous tissue of these areas.
The reticular formation plays a fundamental role in regulating one’s level of consciousness, a process in which the thalamus also especially intervenes. This means that their work has to do with the circadian rhythm and the onset and absence of sleep, among other things.
On the other hand, another function of this network of neurons is the regulation of the state of excitement, or state of alert, a process parallel to that of the regulation of the conscious state.
As the reticular formation is at the entrance to the brain through its areas closest to the spinal cord, it also acts by filtering the information that comes from the senses, selecting pieces of data and discarding irrelevant parts that do not reach the brain. consciousness. Likewise, its relationship with attentional and consciousness processes means that it intervenes in the perception of physical pain and in the processes of habituation to repetitive stimuli.
Besides, reticular formation influences involuntary and automatic movements, such as those that serve to maintain vital signs (heartbeat, for example). In that sense, it is one of the components of the nervous system without which we could not live.
His parts
The reticular formation can be divided into the following parts.
1. Central group of nuclei
A region of the reticular formation that is in turn divided into posterolateral nuclei and medial nuclei.
2. Lateral group of nuclei
Divided into reticular nucleus of the pontic tegmentum, lateral and paramedian nucleus.
3. Medium group of nuclei
Also known as raphe nuclei, located in the medial area of the brain stem. It is divided into the dark nucleus of the raphe and the great nucleus of the raphe.
Diseases that affect the reticular formation are usually very serious, since interference with this brain region produces coma or death.
For example, advanced Parkinson’s disease can deteriorate this network of neurons, as it expands throughout the nervous system. Similarly, narcolepsy, directly involved in altered states of consciousness, produces harmful effects on the reticular formation.
Another disease related to this neural network is cataplexy, whose main symptom is loss of muscle tone; Somehow, in a waking state the body begins to behave as if it were in a REM phase of sleep, which means that the brain is disconnected from the muscles.
Beyond diseases linked to deterioration processes of unknown causes or to the action of viruses, lesions can also seriously alter the functioning of the reticular formation, leading to coma or brain death in a high number of cases.
This is one of the most vulnerable areas of the nervous system, not only because it intervenes directly in the state of consciousness, but because it participates in the maintenance of basic vital functions without which sudden death occurs due to hypoxia in the brain. That is why the functioning of this region is considered a more reliable indicator of the presence of life even than the recording of electrical activity through techniques such as EEG in more superficial areas of the cerebral cortex.
