Waves of Fluid Bathe the Sleeping Brain

Very recommendable! Researchers are finding more important answers to why humans sleep!


"It was this idea of CSF [cerebrospinal fluid] as a brain wash—combined with recent evidence showing that sleep is important for clearing toxic metabolic waste products from the brain—that led Boston University’s Laura Lewis and colleagues to investigate what CSF does during sleep. For the current study, they designed a new approach combining simultaneous electroencephalograms (EEGs) to measure the brain’s electrical activity and blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) to collect blood oxygen levels and the flow of CSF in the brain."


Lot's of brain activity while you sleep:

"But in their sleeping subjects, they saw large waves of CSF flow into the fourth ventricle of the brain about every 20 seconds. Plus, the CSF dynamics were coupled to the brain’s electrical activity. Specifically, an electrical slow wave and corresponding increase in blood flow was followed a few seconds later by a decrease in blood oxygenation and volume and then a surge of CSF."


Waves of Fluid Bathe the Sleeping Brain, Perhaps to Clear Waste | The Scientist Magazine®: During deep sleep, rhythmic pulses of cerebrospinal fluid are coupled with slow waves of electrical activity and fluctuating blood levels in the human brain.