The Glymphatic Clearance System: Brain Washing During Sleep

While you are awake, your brain cells are constantly consuming energy and producing metabolic byproducts. In any other organ, the lymphatic system drains this waste. However, the brain is walled off by the blood-brain barrier. To solve this, the brain uses its own specialized cleaning mechanism: the glymphatic clearance system.

The Cleaning Cycle

The glymphatic system is almost exclusively active during slow-wave Deep Sleep (Stages 3 and 4 of NREM sleep).

The Circadian Gate

Glymphatic clearance is highly synchronized with your circadian rhythm. Melatonin and a drop in core body temperature are both prerequisites to enter the deep sleep stages where astrocytes shrink.

> Chronic sleep deprivation or sleeping at irregular times restricts the glymphatic system from finishing its cycle, leading to the accumulation of plaque and cognitive fatigue.