Learn about the mysterious

For centuries, no one has confirmed the presence of the lymphatic system - which functions to drain waste in the human brain. And recently, the secret of lymphatic vessels in the brain has been revealed by scientists.

For a long time it was thought that the brain was not in this lymphatic system. But after a study on mouse brains two years ago, researchers confirmed the presence of a "waste water" system in the brain. It can also cause many types of illnesses in the body.

In 1816, an Italian surgeon named Paolo Mascagni thought that he saw lymphatic vessels running through the human brain in the corpses where he operated.

If this is true, then it can be said that his eyesight belongs to the excellent. But despite having spent two centuries searching, no one has confirmed this hypothesis.

The lymphatic system is made up of branched vessels that function to transport cells throughout the body thanks to a fluid called lymph. Its purpose is to help fluid flow smoothly in tissues as well as access to immune cells easily. This is to maintain the principle and order deep within the tissues of the human body.

A dense wall of cells called blood-brain barriers separates the circulatory system with gray matter to protect the brain from potential hazards. While most organs in the body have a close relationship with the immune system, our brain is like a fragile art piece that is displayed behind a glass case.

And the absence of small drainage tubes makes our nerve tissue unaffected by contaminants and pathogens. This reinforces the belief that the brain is a special case in anatomy.

Detection of lymphatic system in the brain.(Photo: eLife)

But the question is: are the lymphocytes responsible for moving around the body to detect 'intruders', so how did they go in and out of the brain?

In 2015, this question finally had an answer. By studying the brain of mice, US researchers have identified the presence of a lymphatic system in the central nervous system of mammals.

They said that there may be similar structures in the sclera (a hard membrane located outside the nervous system) in the corpses. The presentation by leading scientist Jonathan Kipnis has received the attention of neuroscientist Daniel S. Reich at the National Institutes of Health.

" I was completely surprised by this new discovery. In medical school, we were taught that the brain does not have lymphatic system. But after Dr. Kipnis's presentation, I thought, maybe we can find it in the human brain. "

To find them, the team injected a substance called gadobutrol into five healthy volunteers, then they conducted a brain scan of the volunteer with magnetic resonance imaging (MRI). This process will help to carefully observe the sclera in the human brain, but unfortunately the team has not seen signs of the lymphatic system.

We can adjust the MRI process, so different shots can show minor differences in anatomical features. So, Reich and his team used various modifications when taking MRI, blood vessels became fuzzy and showed signs of another channel that they thought was the lymphatic system.

To be sure, they use a different color to mark large molecules that are unlikely to mix into blood vessels. When scientists repeat the modified MRI measurements, all signs of mysterious lines have disappeared.

Similar results have been confirmed in squirrel monkeys and physical evidence of blood vessels has also been detected in the sclera in the anatomical brain.

Researcher Reich said: "For years, we all know how fluids get into the brain, and finally we can see that, like other organs in the body, fluid in the brain may escape through the lymphatic system ' .

Next step, scientists will study changes in this drainage system to see if they can help explain more clearly about health conditions.

"These results can fundamentally change the way we think about the relationship between the brain and the immune system , " said Walter J. Koroshetz, director of NINDS .

The discovery and understanding of this mysterious relationship may open up the hope of finding effective treatments for brain-related diseases such as Alzeimers.