and form dynamic networks essential for memory formation and problem-solving.
To perform such energy-demanding tasks, brain cells require fuel.
Their consumption of nutrients from the diet creates metabolic waste in the process.
Researchers at Washington University School of Medicine in St. Louis have found that brain cell activity during sleep is responsible for propelling fluid into, through and out of the brain, cleaning it of debris.
https://medicine.wustl.edu/news/neurons-help-flush-waste-out-of-brain-during-sleep/
The brain’s electrical activity is moving the fluid.
During non-REM sleep, large, slow waves of CEREBROSPINAL FLUID were washing over the brain.
Cerebrospinal Fluid:
A clear, water-like liquid that flows around the brain
During non-REM sleep, neurons start to synchronize, turning on and off at the same time.
“First you would see this electrical wave where all the neurons would go quiet.”
Because the neurons had all momentarily stopped firing, they didn’t need as much oxygen.
That meant less blood would flow to the brain.
Lewis’s team also observed that cerebrospinal fluid would then rush in, filling in the space left behind.
Watch in half Speed (.5) to clearly see the pipes opening.
Brain when Sleeping is on the Left. Awake is on the Right.
Scientists inject tracer molecules
To their surprise, the scientists found that the tracer molecules flowed along a series of channels surrounding blood vessels.
In the brain, blood vessels are surrounded by cells called astrocytes.
Astrocytes cells have projections called end feet that wrap around arteries and veins like a layer of piping.
It was through this pipeline that the molecules traveled.
The system uses pressure to push fluid through the brain.
It's a much faster and more efficient way to carry away waste than diffusion.
Astrocytes are a type of glial cell—a class of cells that support neurons in the nervous system.
The research team named this new system the “glymphatic system”
because it is similar to the body's lymphatic system and is managed by the brain’s glial cells.
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