Q. I once heard you say something to the effect that “The brain and the immune system have their hands so deeply shoved into each other’s pockets that it’s hard to tell which is which.” I loved that metaphor. Is there any new research about that close connection?

A. Actually, there is. Researchers at the University of Virginia School of Medicine have found that the brain is directly connected to the immune system by lymphatic vessels (part of the immune system) previously thought not to exist. They run through the meninges, the three membranes that envelop the brain and spinal cord. This changes entirely the way researchers perceive the neuro-immune interaction. Since it is thought that every neurological disease has an immune component to it, these vessels may play a major role. According to Jonathan Kipnis, a professor in the Department of Neuroscience and director of the Center for Brain Immunology and Glia, this “changes entirely the way we perceive the neuro-immune interaction…We believe that for every neurological disease that has an immune component to it, these vessels may play a major role…In Alzheimer’s, there are accumulations of big protein chunks in the brain. We think they may be accumulating in the brain because they’re not being efficiently removed by these vessels.” And there is an array of neurological diseases, from autism to multiple sclerosis to be reconsidered in light of the presence of something science did not know about or even believe existed. (https://news.virginia.edu/content/researchers-find-textbook-altering-link-between-brain-immune-system)