Sleep does not help brain wash out toxins, study suggests
Finding that clearance of fluid in mice brains is lower in sleep and anaesthesia runs counter to dominant view in neuroscience
The restorative effect of a good night’s rest is widely recognised and the popular scientific explanation has been that the brain washes out toxins during sleep.
However, new findings suggest this theory, which has become a dominant view in neuroscience, could be wrong. The study found that the clearance and movement of fluid in the brains of mice was, in fact, markedly reduced during sleep and anaesthesia.
“It sounded like a Nobel prize-winning idea,” said Prof Nick Franks, a professor of biophysics and anaesthetics at Imperial College London, and co-lead of the study.
“If you are sleep-deprived, countless things go wrong – you don’t remember things clearly, hand-eye coordination is poor,” he added. “The idea that your brain is doing this basic housekeeping during sleep just seems to make sense.”
However, there was only indirect evidence that the brain’s waste-removal system ramps up activity during sleep, Franks said.
