It may not sound like much to those without neuroscience degrees: A researcher at the University of Virginia spotted a lymphatic vessel while studying the brain of a mouse.

But the reason words like "stunning," "dazzling," and "landmark" are being used to describe the finding is that these vessels aren't supposed to be present in brains.

Their presence suggests that our brain is directly connected to our immune system, a discovery that overturns previously accepted medical knowledge and has "significant implications" for the study of neurological diseases such as Alzheimer's and multiple sclerosis, reports Gizmag.

“The first time these guys showed me the basic result, I just said one sentence: ‘They’ll have to change the textbooks,'" says Kevin Lee, chair of UVA's department of neuroscience. So how could scientists mapping the human body all these years have missed this? "The elusive lymphatic vessel hid in plain sight, throughout decades of research, because it was very small and tucked behind a major blood vessel," explains Business Insider. The website says the study in Nature is creating a buzz in the field, though it's not being met with total surprise because previous research had at least hinted at such a result. The next big step will be to try to confirm the findings in humans. As for the potential health implications: "In biology and medicine, if you understand something, you [can start to] find new targets for treatments," says one researcher not involved with the study. (Other research suggests that the brains of vets are aging prematurely because of bomb blasts.)

This article originally appeared on Newser: Discovery of Hidden Vessel in Brain Called 'Stunning'

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