Our Brain Has Its Own Cleaning System
If you have been following my blogs for any length of time, you know that I am the brain’s biggest fan! We have such a miraculous organ running everything in us. In that regard, I had to write about the glymphatic system. When I speak about brain health the glymphatic system gets a lot of consideration. After you read this blog you will understand why the glymphatic system is garnering a lot of attention.
The Lymphatic System
Our body is a self-contained system that houses all of the processes necessary for us to survive. You might be familiar with the term lymphatic system. We have a separate circulatory system within our bodies that is made up of an extensive series of vessels and produces a fluid called lymph. This is an exceptionally important circulatory system, but we rarely hear anything of it. One of the lymphatic system’s functions is to flow through each organ, mop up debris, wash it into a network of ducts that eventually drain into blood vessels. Ultimately, our blood circulatory system takes the metabolic debris to the kidneys and liver, where it is eliminated from the body.
Glymphatic System Basics
It was assumed that the brain had a cleaning system also, but researchers didn’t discover it until 2012. Maiken Nedergaard, a Danish neuroscientist from the University of Rochester, discovered the glymphatic system. The name is in reference to the glial cells, which are vital to the waste clearance system. Although we don’t hear a lot about glial cells in discussing the brain, they protect, nourish and insulate the neurons. They also play a role in the immune system. Cerebrospinal fluid surrounding the brain flows into ring-shaped spaces that encircle the blood vessels in the brain. These spaces act as portals for the entry of cerebrospinal fluid into the rest of the brain. The glial cells act as gatekeepers for these portals. Glia wrap around blood vessels and have cellular machinery that takes up cerebrospinal fluid from the ring-shaped spaces and gives it access to neurons and other brain cells. As it flows through the brain, the CSF collects proteins and other debris and carries it to lymphatic ducts, thereby clearing the brain of waste. So, the term glymphatic system is a combination of glia and lymphatic. (sitn.hms.harvard.edu August 21, 2018)
The Glymphatic System Function Depends on Sleep
The brain is very busy while we are sleeping. Not only is that the time that memory formation and consolidation occur, but it is the time that the glymphatic system flushes out the toxins and debris the brain accumulates during the day. The debris consists of mostly leftover proteins, which when left alone, can form clumps that are toxic to the brain. Specifically, clumping of beta amyloid has been linked to decreases in cognition, memory, and overall brain function in people with Alzheimer’s disease.
It turns out that the slow and steady brain and cardiopulmonary activity associated with deep non-REM sleep are optimal for the glymphatic system to clear waste that has accumulated during the day from the brain. On the opposite side of this, research has uncovered that there is a dramatic decrease in waste elimination during periods of prolonged wakefulness. Lack of deep sleep is a primary risk factor for the development of Alzheimer’s disease.
The Role of Exercise in Glymphatic System Function
Early in 2018, the research team of Maiken Nedergaard demonstrated in a new study that exercise can positively affect the function of the glymphatic system. The study measured glymphatic flow in mice exercising on a running wheel. After five weeks it was reported that the mice that exercised had a two-fold increase in glymphatic flow over the sedentary mice. This study provided the date that supported the brain-boosting effects of exercise.
Final thoughts: Make sleep an important part of your healthy lifestyle. It is critical for memory formation and consolidation, as well as, having a clean, high functioning brain.
Andreone, B. (August 21, 2018). Clearing out the junk: healthy lifestyle choices boost brain waste disposal. Retrieved August 13, 2019 from https://sitn.hms.harvard.edu/flash/2018/clearing-junk-healthy-lifestyle-choices-boost-brain-waste-disposal
Collado, C. (August 2019). But what about toxins in the brain? Help! Your brain has a microscopic cleaning system, the glymphatic system. Retrieved August 14, 2019 from https://www.sinusitiswellness.com/but-what-about-toxins-in-the-brain-has-a-microscopic-cleaning-system-the-glymphatic-system/
Newman, T. (June 21, 2019). How does your brain take out the trash? Retrieved August 13, 2019 from https://www.medicalnewstoday.com/articles/325493.php
University of Rochester Medical Center. (February 27, 2019). Not all sleep is equal when it comes to cleaning the brain. Retrieved August 13, 2019 from https://www.sciencedaily.com/releases/2019/02/190227173111.htm