The brain not only collaborates with the immune system, but even directs it from the shadows. This finding suggests that emotion, immunity and cancer are related.
The journal Nature points out in a report that a body of recent research on the brain has been able to determine that a special immune system protects our gray matter.
He adds that it is an unfinished discovery, because various lines of research are still open today documenting this appreciation of scientists, which cannot yet be considered conclusive.
However, this perspective opens up unsuspected possibilities not only for a better understanding of the brain, but also for original treatments for neurodegenerative diseases that today are considered unbeatable, the magazine states.
One of the first recent findings is that the brain and the immune system are closely relatedevidence that has replaced the old belief that the brain was fortified at the top of the body, with long-lived cells entrenched behind the insurmountable blood-brain barrier, living outside the life-preserving immune system.
This belief began to crumble when immune cells were discovered in the 1990s that protected neurons against an acute injury to the nervous system.
Later it was even found that immune cells are active at the borders of the brain, but it has not been possible to determine with certainty whether they protect the gray matter from disease or instead contribute to its expansion.
Another recent finding indicates that immune cells abound at the border of the brain, many of them identical to those present in other parts of the body, and that even the bone marrow of the skull can produce these defensive cells, thus forming a kind of immune body. of security of the brain to prevent possible pathogenic aggressions.
The discoveries about the brain’s defensive strategies have not stopped there: it also has a series of channels on its surface equipped with immune cells that form its own lymphatic system: it can record everything that happens in the body and detect any alteration.
And something no less surprising. All these indications of immune cells in the brain, own and foreign, are complemented by other evidence: not only do they protect the gray matter, but they are also involved in the neurodevelopment.
This means that their role is not only defensive, but that they are also available to healthy brains, although it is still not well understood how immune cells communicate with the brain: it is supposed to be through molecular messengers called cytokines.
This aspect is also another revelation, because these molecular messengers are related to behavior and can trigger reactions typical of a disease, such as sleeping more than necessary.
It is also suspected that they can affect memory, learning and social behaviors, and could even be related to autistic disorder.
And the latest thing that has changed everything is the suspicion that the brain, unknown until now, may be directing the immune system of the whole body, since links have been found between emotion, immunity and cancer.
This means that stimulating certain neurons can influence the immune response to any abnormality, especially since it has also been proven that immune cells can relate to neurons so that they remember past episodes and avoid damage in the present.
These findings are not only valid for neurodegenerative diseases, but may also be useful for developing new therapies for diseases such as psoriasis or intestinal disorders.
Nature also highlights in its report that all these potential developments related to the brain are in their infancy and that there is still a lot of work to be done to decipher which populations of neurons are involved in the different immune processes.
And it concludes, however, that this preliminary knowledge is being applied to the rejuvenation of the human immune system, in order to combat Alzheimer’s disease, which opens the way to new therapies for neurodegenerative diseases in relatively reasonable time frames.
Guardians of the brain: how a special immune system protects our gray matter. Diana Kwon. Nature 606, 22-24. (2022). DOI:https://doi.org/10.1038/d41586-022-01502-8