The sleep-wake cycle affects tau protein levels in brain fluid of mice and spinal fluid of humans

Mouse interstitial fluid tau levels increased by approximately 90% during normal wakefulness compared to sleep.

• Chronic sleep deprivation raised interstitial fluid tau levels by about 100%.
• Human cerebrospinal fluid tau levels increased by more than 50% during sleep deprivation.
• Chronic sleep deprivation was associated with increased spreading of tau pathology in a tau seeding-and-spreading model.
• Chemogenetically induced wakefulness in mice significantly elevated both interstitial fluid Aβ and tau levels.
• The sleep-wake cycle is linked to the regulation of interstitial fluid tau levels.

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