Sleep isn’t downtime for your brain. It’s a flush cycle.
During sleep, the spaces between brain cells expand ~60%. CSF flows through and washes out metabolic waste, including β-amyloid, the peptide that aggregates in Alzheimer’s. Clearance is ~2x faster than during wake.
Mechanism characterized by Nedergaard’s lab in 2013 (Xie et al., Science). Called the glymphatic system. The brain has no conventional lymphatics. This is the workaround.
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