How your brain 'washes' itself as you sleep

WE ALL know how important sleep is for our well-being.

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It plays a huge role in everything from our mood to how well we think. Now new research has given scientists a deeper understanding of sleep's impact: it not only refreshes our minds, it also quite literally "washes" our brains.

A study involving mice has provided insight into how this "flushing" process happens and confirmed that deep sleep phases are vital for keeping our brains healthy.

This cleaning process is based on something called the glymphatic system. Think of it as a brain irrigation system that moves cerebrospinal fluid around to flush out waste products, including harmful proteins that build up while we're awake. Studies suggest that this cleaning mostly happens during non-rapid eye movement (REM) deep sleep when brain activity is slow, unlike REM sleep when most of our dreaming occurs.