Brainwashing is real—but it’s not what you think

<p><b>New research into how the brain disposes of waste products could help in the fight against Alzheimer’s, Parkinson’s and more.</b></p>

<h4>In the news</h4> <p>If you are of a certain age, the very term “brain waste” may bring to mind characters like the high school surfer stoner <a href="https://www.google.com/search?gs\_ssp=eJzj4tLP1TcwyitPqbA0YPTiyUpNS1MoLshMzs\_JBABqLAhx\&amp;q=jeff\+spicoli\&amp;rlz=1C1GCEW\_enUS1079US1079\&amp;oq=jeff\+spic\&amp;gs\_lcrp=EgZjaHJvbWUqCggBEC4YsQMYgAQyDQgAEAAY4wIYsQMYgAQyCggBEC4YsQMYgAQyBggCEEUYOTIHCAMQABiABDIHCAQQABiABDIHCAUQABiABDIHCAYQABiABDIHCAcQABiABDIHCAgQABiABDIHCAkQABiABNIBCTYxMTNqMGoxNagCCLACAQ\&amp;sourceid=chrome\&amp;ie=UTF-8" target="_blank">Jeff Spicoli</a> played by Sean Penn in the early ‘80s classic movie <i>Fast Times at Ridgemont High</i>. But set that image aside, dude—there’s a serious point to be made.</p> <p>The human brain contains about 170 billion cells. As those cells go about their business, they produce waste. “To stay healthy,” <a href="https://www.npr.org/sections/shots-health-news/2024/06/26/g-s1-6177/brain-waste-removal-system-amyloid-alzheimer-toxins" target="_blank">this report notes</a>, “the brain needs to wash away all that debris.”</p> <p>How the brain removes this effluent, and where it goes, has long puzzled science—but a trio of new research papers may provide answers. Moreover, those answers may eventually help researchers understand and fight a wide range of brain disorders.</p> <p>The discovery itself is fascinating. In most mammals’ bodies, it’s the lymphatic system that maintains fluid levels and filters waste products. But the brain lacks the lymphatic system’s tiny waste-removal tubes (think of them as a sewer system if you like). Hence the puzzlement over how brain waste is processed.</p> <p>Now, multiple groups of researchers have identified what they call the “glymphatic system,” which “<a href="https://www.psychiatrist.com/news/researchers-discover-waste-disposal-system-in-the-brain/" target="_blank">manages cerebrospinal fluid flow through the brain</a>” and handles waste removal. As it turns out, the slow electrical waves that move through the brain during sleep act as a signal that ingeniously transforms neurons into pumps that, in turn, push healthy fluids into the brain—and waste products from it.</p> <h4>The Cognizant take</h4> <p>One of the exciting takeaways from this research is that it may lead to new ways to fight brain disorders. Through experimentations with mice that have a form of Alzheimer’s, an MIT-based team <a href="https://www.nature.com/articles/s41586-024-07132-6" target="_blank">devised a way</a> to increase fluid flow to and from the brain. The latter fluid was shown to carry amyloid—a substance that builds up in the brains of human Alzheimer’s patients.</p> <p>Much confirmation and refinement remains to be done (anatomical differences between rodents and humans “are pretty substantial,&quot; as one researcher pointed out). But when taken together, the studies suggest that keeping the brain's waste-clearance system healthy demands two interrelated steps: pushing waste into the cerebrospinal fluid that surrounds the brain, and then moving it into the lymphatic system—and out of the body.</p> <p>In addition to Alzheimer’s, other disorders such as Parkinson’s, headaches and even depression may be linked to malfunctioning brain-waste removal. So, the identification of the glymphatic system and ways to improve its function could benefit millions.</p>