- During deep sleep, the brain may be tidying up the detritus that accumulates during a hard day of thinking, a recent study suggests.
They found that the blood flow to the brain diminishes, allowing for an influx of clear, colorless cerebrospinal fluid . That fluid surges in and sloshes around, washing away the day's detritus of proteins and other waste substances that might harm the brain if they aren't cleared out. "Previous studies in animals from other labs have shown that during sleep, proteins such as beta-amyloid are cleared more rapidly from the brain," Lewis said in an email."Based on these studies, we wondered why this might occur and we wanted to ask whether CSF changes during sleep because CSF is thought to be important for waste removal.
The new research shows how the rhythmic flow of fluid during deep sleep could be the way the brain washes away waste, Danish researchers write in a commentary that accompanied the new study.