OCT 10, 2017 07:07 AM PDT
Brain Drain: It's Real and Not What You Think
3 37 1813

The lymphatic system is the body's way of keeping cells moving along. It's an integral part of the circulatory system as well as the immune system. Lymph is actually a clear fluid that carries immune cells to lymph nodes.

When the body is under attack from an infection the lymph system goes into gear by getting rid of the cellular waste of increased white blood cells that fight off infection. Lymphatic vessels were discovered in the brain in 1816, but no organized system was found, and research has largely ignored their existence.

New work from a team at the National Institutes of Health has shown that these vessels actually drain waste from the brain. The study is the first to show that there is an actual interaction between the brain and the immune system and that "brain drain" is a real thing.

Dr. Daniel S. Reich, M.D., Ph.D., is a senior investigator at the NIH's National Institute of Neurological Disorders and Stroke (NINDS) explained, "We literally watched people's brains drain fluid into these vessels. We hope that our results provide new insights to a variety of neurological disorders."

Using magnetic resonance imaging (MRI) scans, Dr. Reich and his team looked at lymphatic vessels located in the dura of the brain. The dura is a protective outer coating of the brain that sits between brain tissue and the skull. Dr. Reich saw a presentation by Dr. Jonathan Kipnis, a researcher at the University of Virginia and the author of a 2015 study that found evidence of drainage happening in the lymphatic vessels of the mouse brain. This study made an impression on Reich since his medical school training had been the standard theory that there was no lymphatic activity in the brain. Knowing that there was evidence of it in a mouse model spurred him to look for it in humans.

Reich used MRI scans of healthy volunteers. The study participants were injected with a dye called gadobutrol which is typically used to look for damaged blood vessels in patients with MS or cancer. The gadobutrol stayed in the dura because the molecules in it are small enough so it can leak out of blood vessels, but too large to fit through the blood-brain barrier and enter other parts of the brain. In essence, the dye was a Goldilocks solution, being "just right." It took a little tuning of the scanners to pick up the drainage, but it was worth the effort. With the correct settings, the researchers could see the dye in the dura leaking out of the blood vessels and passing into the adjacent lymphatic vessels.

In addition to the human studies, the team looked at autopsy studies of nonhuman primates to see if the lymphatic system was typical in the mammalian brain and they found evidence in these examinations that confirmed the results of the human studies. Dr. Reich and his team hope to continue the research to see if the draining is disrupted in patients with inflammatory neurological disorders like multiple sclerosis. The video below has more information on this important discovery; check it out.

Sources: NIH, Barts/London Neuroimmunology Group MS Blog, eLife

About the Author
  • I'm a writer living in the Boston area. My interests include cancer research, cardiology and neuroscience. I want to be part of using the Internet and social media to educate professionals and patients in a collaborative environment.
You May Also Like
MAR 25, 2018
Cell & Molecular Biology
MAR 25, 2018
The Brain's Storage Capacity can Expand
Researchers have discovered that synapses in the brain strike a balance; as some get larger, others shrink.
APR 20, 2018
Clinical & Molecular DX
APR 20, 2018
One Concussion Raises the Risk of Parkinson's Disease
A diagnosis of a mild concussion or a traumatic brain injury (TBI) raises the risk of developing Parkinson’s disease, according to a new study from t
APR 26, 2018
Neuroscience
APR 26, 2018
Dopamine Levels Could be a Biomarker for Alzheimer's
In the field of neuroscience, the search for information on how to diagnose, treat and perhaps even prevent Alzheimer's disease is a priority. Alzheime
MAY 16, 2018
Health & Medicine
MAY 16, 2018
Cases of Major Depression On The Rise
Major depression is a serious mental health condition, and it’s on the rise among Americans of all ages. In a study done as part of the Health of Ame
MAY 22, 2018
Neuroscience
MAY 22, 2018
A Runny Nose That Was More Than a Cold
Spring is entirely upon us, and that means some can suffer from allergies. A runny nose is a common symptom, and one Nebraska woman thought the pollen and
MAY 31, 2018
Immunology
MAY 31, 2018
Immunosuppressant Drugs to Prevent Parkinson's Disease
Certain immune activity could be increasing a person’s risk of developing Parkinson’s disease (PD), but immunosuppressant drugs might solve the
Loading Comments...