Textbooks of medicine say that there is no direct connection between the brain and the lymphatic system. Yet, a paper published recently in the journal Nature refers to the discovery of exactly such a connection.
The researchers are from the School of Medicine, University of Virginia. While it is quite a startling discovery in itself, it gains significance because it could lead to a breakthrough in the treatment of diseases such as Alzheimer’s disease, multiple sclerosis etc.
The lymphatic system consists of vessels that carry a transparent fluid, the lymph, which helps rid the body of toxins and other unwanted substances. It also forms an important part of the body’s immune system. Until now, it was believed that this system is not connected to the brain. In a stunning discovery based on study of mouse brain, the researchers from University of Virginia have identified connections between the lymphatic system of the mouse and its brain. The group has discovered a similar structure in human dura (tissue that covers the brain), but write in the paper that “further studies will be necessary to fully characterize the location and organization of meningeal lymphatic vessels in the human central nervous system.”
“It is true that a direct connection between the brain and the lymphatic has never been established before… When we started that project, we were not looking for this, our question was: since there are immune cells in the meninges [layers of tissue that cover the brain and spinal cord], where do they enter and how do they leave the brain. And while addressing those questions, we came across the discovery of these lymphatic vessels,” says Antoine Louveau of Centre for Brain Immunology and Glia, School of Medicine, University of Virginia, corresponding author of the paper, in an email to this correspondent.
This discovery can be very significant in the treatment of neurological conditions. Jonathan Kipnis, director of University of Virginia’s Centre for Brain Immunology and Glia, notes in an email, “I want to see what the role of these vessels is, in different neurological disorders. If we [have] discovered a new structure — it is cool. But, if we [have] discovered a new clue to better understanding and curing human diseases, then it is a real breakthrough. Time will tell.” When asked what diseases he is referring to, Dr Kipnis adds, “We are particularly interested in Multiple Sclerosis, meningitis, CNS trauma, Alzheimer’s [disease] and brain tumours, to list a few…”
