A shocking new discovery shows the brain is directly connected to the immune system through vessels previously unknown to science.
The body has been exhaustively mapped throughout the decades, so researchers were shocked to see these lymphatic blood vessels had escaped detection, the Univeristy of Virginia School of Medicine reported. These findings could lead to new treatments for nurological diseases such as Alzheimer's and multiple sclerosis.
"Instead of asking, 'how do we study the immune response of the brain?' 'Why do multiple sclerosis patients have the immune attacks?' now we can approach this mechanistically. Because the brain is like every other tissue connected to the peripheralimmune system through meningeal lymphatic vessels," said Jonathan Kipnis, professor in the UVA Department of Neuroscience and director of UVA's Center for Brain Immunology and Glia (BIG). "It changes entirely the way we perceive the neuro-immune interaction. We always perceived it before as something esoteric that can't be studied. But now we can ask mechanistic questions."
The elusive vessels were detected after Antoine Louveau, a postdoctoral fellow in Kipnis' lab, created a new method for mounting mouse meninges on a slide so they could be examined in their entirety.
"It was fairly easy, actually," Louveau said. "There was one trick: We fixed the meninges within the skullcap, so that the tissue is secured in its physiological condition, and then we dissected it. If we had done it the other way around, it wouldn't have worked."
The team noticed "vessel-like patterns" in the immune cells on the slides, and found they were lymphatic vessels. This discovery raises a number of questions about how the brain works and what occurs in cases of brain-related diseases.
"In Alzheimer's, there are accumulations of big protein chunks in the brain," Kipnis said. "We think they may be accumulating in the brain because they're not being efficiently removed by these vessels."
The findings were published in a recent edition of the journal Nature.
