We Are “Brainwashed” When We Sleep

New research from Boston University suggests that while you sleep, something amazing is happening within your brain. Your neurons go quiet. A few seconds later, blood flows out of your head. Then, a water liquid called cerebrospinal fluid (CSF) flows in, washing through your brain in rhythmic, pulsing waves. CSF flow and slow-wave activity both help flush toxic, memory-impairing proteins from the brain, helping the brain get rid of accumulated metabolic “trash." The study is the first to illustrate that the brain’s CSF pulses during sleep, and that these motions are closely tied with brain wave activity and blood flow. Researchers hope that it will one day lead to insights about a variety of neurological and psychological disorders that are frequently associated with disrupted sleep patterns, including autism and Alzheimer’s disease.