A unique peek inside the human brain may help explain how it clears away waste like the kind that can build up and lead to Alzheimer’s disease. Brain cells use a lot of nutrients which means they make a lot of waste. Scientists have long thought the brain has special plumbing to flush out cellular trash, especially during sleep – they could see it happening in mice.

But there was only circumstantial evidence of a similar system in people. Now researchers have finally spotted that network of tiny waste-clearing channels in the brains of living people, thanks to a special kind of imaging. “I was skeptical,” said Dr.

Juan Piantino of Oregon Health & Science University, whose team reported the findings Monday. “We needed this piece to say this happens in humans, too.” ALSO READ: Habits to keep brain active and alive: Unlock the secret to a sharp mind The study was published in the journal Proceedings of the National Academy of Sciences.

The brain is remarkably active during sleep. One reason seems to be that's the time it does a deep clean. And that's gotten attention because while losing a good night’s sleep muddles people’s thinking, chronic sleep deprivation also is considered a risk factor for dementia.

So how does the brain cleanse itself? Over a decade ago, scientists at the University of Rochester first reported finding a network they dubbed the “glymphatic system." Cerebrospinal fluid uses channels surrounding blood vessels to get deep into tissue and mo.