Neuroscientists have made an unexpected discovery that brings new meaning to the term “brainwash.”

In a study of mice, researchers found that the brains of awake mice were dry, whereas the brains of sleeping mice were full of fluid.

When mice fell asleep under the microscope, “It was almost like you opened a faucet,” said lead researcher Maiken Nedergaard.

The cerebrospinal fluid increased in volume by at least 60% during sleep. The benefit of the extra fluid? It washed away unwanted debris.

The discovery helps us understand why sleep is mandatory for every animal. But the findings are important for another reason. The sleep-induced surge in brain fluid also washed away harmful protein deposits that cause neurodegenerative diseases like Alzheimer’s.

Researchers admit that, until now, there has been little focus on the area between cells. But now neuroscientists like Randall Bateman say they’d be fools not to pay attention to the space between brain cells. If the brainwash occurs in people the same way it occurs in mice, it could completely change the way doctors treat diseases like Alzheimer’s.

So what’s next?

Some imagine a drug that might trigger a brainwash to cleanse the toxic gunk from our brains. But don’t throw out the coffee quite yet. Even if science leads to such medication, it won’t eliminate the need for sleep altogether. “Sleep has become such an integral part of life on this planet that it serves additional functions besides clearing substances out of the brain,” says Bateman.

For More Information:

• Sleep allows brain to wash out junk, Science News
• A good night of sleep is like hosing down your filthy brain, Gizmodo