AI reveals how the brain clears harmful waste during sleep

Engineers routinely measure how fluids move through pipes, rivers, and blood vessels. But tracking the fluid that carries waste out of the brain has proved far more difficult. The fluid that cleans the brain during sleep moves far too slowly for any standard scanner to track. No one had measured its speed deep inside a living animal – until now.

AI reveals how the brain clears harmful waste during sleep. Engineers routinely measure how fluids move through pipes, rivers, and blood vessels. But tracking the fluid that carries waste out of the brain has proved far more difficult. The fluid that cleans the brain during sleep moves far too slowly for any standard scanner to track. No one had measured its speed deep inside a living animal – until now. Washing the sleeping brain Scientists call this overnight cleaning network the glymphatic system. During deep sleep, waterlike fluid moves through the brain, carrying away the debris generated by a day’s worth of activity. Neuroscientist Maiken Nedergaard first described the system in 2012, and the stakes became clear quickly. Among the waste it clears are sticky amyloid beta proteins – the same fragments that clump into plaques in the br...