How we ‘brainwash’ ourselves while we sleep

By Imogen Howse via SWNS

Brainwashing is more common than we think after scientists discover we do it every night.

Neurobiologists found our brains wash themselves out during sleep – using the downtime to get rid of all the waste produced from carrying out our day-to-day tasks.

Brain waves combine to propel liquid through the brain tissue and flush out any debris, using varying levels of force throughout the process in a way ‘similar to washing the dishes’.

Scientists believe this revelation may provide new ways to tackle or prevent diseases such as Alzheimer’s or Parkinson’s, as both involve too much waste building up in the brain.

A research team from Washington University School of Medicine in Missouri studied the brains of sleeping mice to better understand what our brains do while our bodies are sleeping.

The team already understood that our brains use this downtime to essentially ‘wash’ themselves of the waste created by carrying out various energy-demanding tasks – such as controlling our thoughts, emotions, and movements – but they were unsure how exactly this was done.

Their findings, published in the journal Nature, revealed that individual nerve cells, known as neurons, coordinate to produce rhythmic brain waves that flush fluids through dense brain tissue.

This cerebrospinal fluid washes the brain tissue by weaving through intricate cellular webs, collecting and removing excess waste as it travels.

If the waste is not removed, it could accumulate in the brain and cause diseases such as Alzheimer’s or Parkinson’s.

Senior author Dr Jonathan Kipnis, a neuroscientist and professor at Washington University School of Medicine, explained: “It is critical that the brain disposes of metabolic waste that can build up and contribute to neurodegenerative diseases.

“We knew that sleep was a time when the brain initiates a cleaning process to flush out waste and toxins it accumulates during wakefulness, but we didn’t know how that happens.

“Our recent findings might be able to point us toward strategies and potential therapies to speed up the removal of this damaging waste."

Kipnis said this could help people survive on less sleep - and be of particular use to those suffering from insomnia.

“If we can enhance this brain cleansing process, perhaps it’s possible to sleep less and remain healthy," he said.

“Not everyone has the benefit of eight hours of sleep each night, and loss of sleep has an impact on health.

“Could people sleep less if they clean waste from their brains more efficiently?

“Could we help people living with insomnia by enhancing their brain’s cleaning abilities so they can get by on less sleep?”

According to first author Dr. Li-Feng Jiang-Xie, the team's study could also represent a breakthrough in the treatment and prevention of various neurodegenerative diseases - particularly Alzheimer's and Parkinson's.

He said: “If we can build on our research and better understand the brain cleaning process, there is the possibility of delaying or even preventing neurological diseases, including Alzheimer's and Parkinson's disease, in which excess waste – such as metabolic waste and junk proteins – accumulate in the brain and lead to neurodegeneration.”

Discussing what they discovered about sleep-time 'brainwashing', Dr. Jiang-Xie said the process can be compared to washing dishes.

He said: “We think the brain-cleaning process is similar to washing dishes.

“You start, for example, with a large, slow, rhythmic wiping motion to clean soluble wastes splattered across the plate.

“Then, you decrease the range of the motion and increase the speed of these movements to remove particularly sticky food waste on the plate.

“Despite the varying amplitude and rhythm of your hand movements, the overarching objective remains consistent: to remove different types of waste from dishes.

The neuroscientist concluded: “Maybe the brain adjusts its cleaning method depending on the type and amount of waste.”