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www.neurosciencenews.com_neuroscience-topics 2015 00266.txt.txt

#Researchers Find Missing Link Between the Brain and Immune system In a stunning discovery that overturns decades of textbook teaching, researchers at the University of Virginia School of medicine have determined that the brain is connected directly to the immune system by vessels previously thought not to exist. That such vessels could have escaped detection when the lymphatic system has been mapped so thoroughly throughout the body is surprising on its own, but the true significance of the discovery lies in the effects it could have on the study and treatment of neurological diseases ranging from autism to Alzheimer disease to multiple sclerosis. nstead of asking, ow do we study the immune response of the brain? hy 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 peripheral immune system through meningeal lymphatic vessels, said Jonathan Kipnis, Phd, professor in the UVA Department of Neuroscience and director of UVA Center for Brain Immunology and Glia (BIG). t changes entirely the way we perceive the neuro-immune interaction. We always perceived it before as something esoteric that can be studied. But now we can ask mechanistic questions. e believe that for every neurological disease that has an immune component to it, these vessels may play a major role, Kipnis said. ard to imagine that these vessels would not be involved in a neurological disease with an immune component. New Discovery in Human body Kevin Lee, Phd, chairman of the UVA Department of Neuroscience, described his reaction to the discovery by Kipnislab: he first time these guys showed me the basic result, I just said one sentence: heyl have to change 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 theye done many studies since then to bolster the finding that it will fundamentally change the way people look at the central nervous system relationship with the immune system. Even Kipnis was skeptical initially. really did not believe there are structures in the body that we are not aware of. I thought the body was mapped, he said. thought that these discoveries ended somewhere around the middle of the last century. But apparently they have not. ery Well Hidden The discovery was made possible by the work of Antoine Louveau Phd, a postdoctoral fellow in Kipnislab. The vessels were detected after Louveau developed a method to mount a mouse meninges the membranes covering the brain on a single slide so that they could be examined as a whole. t was fairly easy, actually, he said. here 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 have worked. After noticing vessel-like patterns in the distribution of immune cells on his slides, he tested for lymphatic vessels and there they were. The impossible existed. The soft-spoken Louveau recalled the moment: called Jony Kipnis to the microscope and I said, think we have something.''As to how the brain lymphatic vessels managed to escape notice all this time, Kipnis described them as ery well hiddenand noted that they follow a major blood vessel down into the sinuses, an area difficult to image. t so close to the blood vessel, you just miss it, he said. f you don know what youe after, you just miss it. ive imaging of these vessels was crucial to demonstrate their function, and it would not be possible without collaboration with Tajie Harris, Kipnis noted. Harris, a Phd, is an assistant professor of neuroscience and a member of the BIG center. Kipnis also saluted the henomenalsurgical skills of Igor Smirnov a research associate in the Kipnis lab whose work was critical to the imaging success of the study. Alzheimer, Autism, MS and Beyond The unexpected presence of the lymphatic vessels raises a tremendous number of questions that now need answers, both about the workings of the brain and the diseases that plague it. For example, take Alzheimer disease. n Alzheimer, there are accumulations of big protein chunks in the brain, Kipnis said. e think they may be accumulating in the brain because theye not being removed efficiently by these vessels. He noted that the vessels look different with age so the role they play in aging is another avenue to explore. And there an enormous array of other neurological diseases, from autism to multiple sclerosis, that must be reconsidered in light of the presence of something science insisted did not exist u

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