- Pipeline-like vessels found in the dura region of the brain.
- The brain drains out fluid through these vessels.
- The brain may have lymphatic system.
The lymphatic system is our body's 'sewerage system'. It maintains fluid levels in our body tissues by removing all fluids that leak out of our blood vessels. The lymphatic system is important for the optimal functioning of our general and specific immune responses. The lymph nodes monitor the lymph flowing into them and produce cells and antibodies which protect our body from infection and disease. The lymphatic system also plays an important role in the absorption of fats from the intestine.
The Brain is Draining Out Fluid through Vessels
‘Like other organs in the body, the brain too may be draining out fluid through the lymphatic system.’
Recent research at the National Institutes of Health found that the brain is draining out fluids through vessels. The study found pipeline-like vessels in the dura region of the brain.
Finding Vessels in the Brain
To look for the vessels, Dr. Reich's team at the National Institute used MRI to scan the brains of five healthy volunteers who had been injected with gadobutrol, a magnetic dye typically used to visualize brain blood vessels damaged by diseases, such as multiple sclerosis or cancer. The dye molecules are small enough to leak out of blood vessels in the dura but too big to pass through the blood-brain barrier and enter other parts of the brain.
At first, when the researchers set the MRI to see blood vessels, the dura lit up brightly, and they could not see any signs of the lymphatic system. But, when they tuned the scanner differently, the blood vessels disappeared, and the researchers saw that dura also contained smaller but almost equally bright spots and lines which they suspected were lymph vessels. The results suggested that the dye leaked out of the blood vessels, flowed through the dura and into neighboring lymphatic vessels.
To test this idea, the researchers performed another round of scans on two subjects after first injecting them with a second dye made up of larger molecules that leak much less out of blood vessels. In contrast with the first round of scans, the researchers saw blood vessels in the dura but no lymph vessels regardless of how they tuned the scanner, confirming their suspicions.
There May be a Lymphatic System in the Brain
Daniel S. Reich, M.D., Ph.D., senior investigator at the NIH's National Institute of Neurological Disorders and Stroke (NINDS) reported observing the brain draining fluid into these vessels. This could suggest that the brain has a lymphatic system.
The study also found evidence for blood and lymph vessels in the dura of autopsied human brain tissue. Moreover, their brain scans and autopsy studies of brains from nonhuman primates confirmed the results seen in humans, suggesting the lymphatic system is a common feature of mammalian brains.
NIH Researchers Uncover Drain Pipes in Our Brains - (https://www.ninds.nih.gov/News-Events/News-and-Press-Releases/Press-Releases/NIH-researchers-uncover-drain-pipes-our-brains)