Scientists discover a new structure in the human brain | Science and health

Now, thanks to advances in neuroimaging techniques and molecular biology, scientists from the United States and Denmark have discovered a new structure in the brain.

They named it SLYM, which stands for Subarachnoid Lymphoma Type.

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The expert group described the structure as a little-known component of brain anatomy that serves as a protective barrier and platform for monitoring infections and infections.

The discovery, published in the specialized journal Science, was made by scientists from the Center for Translational Neuromedicine at the University of Rochester (USA) and the University of Copenhagen (Denmark).

The brain is covered by three membranes called the meninges: the pia mater, arachnoid mater, and the dura mater. These tissues create a barrier between the central nervous system and the rest of the body.

Between the pia mater and the arachnoid is an opening known as the subarachnoid space, which is filled with cerebrospinal fluid. These things flow in and around the brain to help lining it and as a source of nutrients.

The newly discovered new structure would be a fourth membrane located within the subarachnoid space, above the pia mater, which is the innermost membrane.

As the researchers explain, in addition to coating the organ, SLYM appears to help control the flow of cerebrospinal fluid in and out of the brain.

“Our hypothesis is that SLYM acts as a barrier between the ‘clean’ cerebrospinal fluid, which enters the brain, and the ‘dirty’, which leaves the organ, drawing protein residue with it,” explains neuroscientist Virginia Pla Requina, MD, of the center. in neurological medicine at the University of Copenhagen and one of the study’s authors.

“As a result, the deterioration of this membrane will make it difficult to clean the brain which in turn will affect the function of neurons,” he adds.

Indeed, the researchers believe that the discovery of SLYM represents a new level of regulation in cerebrospinal fluid circulation.

According to them, the presence of the new membrane seems to confirm the complex role that this fluid plays in maintaining the brain’s immune defenses and in transporting and eliminating toxic waste.

Much of this “toxic waste” has been linked to neurodegenerative diseases such as Alzheimer’s and other diseases affecting the central nervous system.

The scientists explained that SLYM is a type of mesenchyme, a type of membrane that covers other parts of the body, such as the lungs and heart.

These tissues protect vital organs and store immune cells.

The American and Danish researchers suggest that SLYM is the intermediate tissue of the central nervous system, lining the blood vessels in the cavity between the brain and the skull.

The newly discovered tissue can also act as a lubricant in this cavity.

“Physiological impulses triggered by the cardiovascular system, respiration and changes in head position continuously move the brain within the cranial cavity,” the researchers explained.

They add, “Like other mesencephalic cells, SLYM can reduce friction between the brain and the skull during these movements.”

The membrane was first described in mice, but the researchers say they were later able to detect it in human brains donated for research as well.

They explained that it could not have been observed before because the material disintegrates when the brain is extracted from the skull during an autopsy.

Moreover, they say, it is a membrane too thin—only a few cells thick—to be seen in living people using conventional imaging.

Ten years ago, the same team of neuroscientists from the Universities of Rochester and Copenhagen transformed understanding of the processes and mechanics of the brain by publishing the discovery of the so-called glymphatic system.

They described the discovery as a mechanism whose function is to remove or clean up the waste that accumulates in the brain.

This substance includes the proteins beta-amyloid and TAU, which appear to be involved in Alzheimer’s disease and accumulate in the brains of patients with this type of dementia.

Since then, several teams of specialists have conducted studies to discover exactly how the glymphatic system works, why it fails sometimes and what is going on in the brains of these affected individuals.

The academics believe that the discovery of the SLYM membrane could have important implications for understanding the precise functions of the glymphatic system.

This, in turn, will open the door to new research that can monitor this structure and look for signs of infection or inflammation behind diseases of the central nervous system.

The researchers suggest, for example, that deterioration of the membranes may make it difficult to remove toxic waste that contributes to the plaques that lead to Alzheimer’s disease.

This structure will also play a role in brain defense, preventing foreign immune cells from contacting the original brain cell population, contributing to inflammation and the development of cognitive decline.

In the coming years, research will be conducted to determine the implications of having SLYM.

But, as neuroscientist Virginia Pla stresses, understanding how this membrane works could be key to creating new therapies, such as drugs that can cross the blood-brain barrier and act directly on the brain.

Moreover, due to its location, the newly discovered structure “could be a key component of inflammatory processes, such as those seen in head injuries, meningitis, and multiple sclerosis.”

Finally, knowing how this membrane changes in response to neurodegeneration or aging could be essential for interventions that attempt to preserve cognitive function.

Professor Jordi Villaplana, from the Department of Biochemistry and Physiology at the University of Barcelona, ​​Spain, considers the possible existence of this membrane “very interesting”.

“It is another element in understanding the functioning of the glymphatic system, about whose structure and function there are still some uncertainties,” says the researcher, who was not directly involved in the study.

“However, from my point of view, the main revolution is the discovery of the glymphatic system itself and its possible involvement in neurodegenerative diseases,” the specialist concludes.

– This text is posted at https://www.bbc.com/portuguese/internacional-64359017