Uncovering the Brain's Lymphatic Drainage System: A New Hub Revealed

How does the brain take out its trash? That is the job of the brain's lymphatic drainage system, and efforts to understand how it works have pushed the boundaries of brain-imaging technologies. A newstudyiniScienceby researchers at the Medical University of South Carolina reveals—for the first time in humans—evidence of a previously unrecognized hub in the brain's lymphatic drainage system—the middle meningeal artery (MMA). Taking advantage of a NASA partnership that provided access to real-time MRI technologies originally developed to study how spaceflight affectsfluid dynamicsin the human brain, the MUSC research team, led by Onder Albayram, Ph.D., tracked cerebrospinal and interstitial fluid flow along the MMA in five healthy participants over a six-hour period. They found that the drainage flow of the cerebrospinal fluid was passive, suggesting lymphatic rather than blood flow. Blood would have had a faster, more dynamic flow. "We saw a flow pattern that didn't behave like blood moving through an artery; it was slower, more like drainage, showing that this vessel is part of the brain's cleanup system," said Albayram, an associate professor in the Department of Pathology and Laboratory Medicine at MUSC.