Neurovascular Process Flushes Toxins from the Brain During Sleep

We spend one third of our lives sleeping: But to what end? One function of sleep is to consolidate memories and to help with subsequent computational challenges. Studies in rodents have suggested another function: During sleep, increased volumes of interstitial fluid drain through a “glymphatic” system — a recently discovered set of small vessels like lymphatics that carry toxins (like β-amyloid) away from the brain (NEJM JW Gen Med Aug 21 2018; [e-pub] and Nature 2018; 560:185). Does this occur in humans?

In a new study, researchers evaluated sleeping humans with prolonged functional magnetic resonance imaging techniques coupled with electroencephalograms and identified a similar phenomenon: Slow-wave sleep leads to reductions in cerebral b…