It’s a stunning discovery that overturns decades of textbook teaching: researchers at the School of Medicine have determined that the brain is directly connected to the immune system by vessels previously thought not to exist. “I really did not believe there were structures in the body that we were not aware of. I thought the body was mapped,” said Jonathan Kipnis, a professor in the Department of Neuroscience and director of the University’s Center for Brain Immunology and Glia. How these vessels could have escaped detection when the lymphatic system has been so thoroughly mapped throughout the body is surprising on its own.

But the true significance of the discovery lies in its ramifications for the study and treatment of neurological diseases ranging from autism to Alzheimer’s disease to multiple sclerosis. Kipnis said researchers no longer need to ask questions such as, “How do we study the immune response of the brain?” or “Why do multiple sclerosis patients have immune system attacks?” “Now we can approach this mechanistically — because the brain is like every other tissue connected to the peripheral immune system through meningeal lymphatic vessels,” Kipnis said. “We believe that for every neurological disease that has an immune component to it, these vessels may play a major role.” Kevin Lee, who chairs the Department of Neuroscience, recalled his reaction the first time researchers in Kipnis’ lab shared their basic result with him.

“I just said one sentence: ‘They’ll have to rewrite the textbooks.’ There has never been a lymphatic system for the central nervous system, and it was very clear from that first singular observation — and they’ve done many studies since then to bolster the finding — that it will fundamentally change the way people look at the central nervous system’s relationship with the immune system,” Lee said.

Read the full article here.