According to a new study published in the Science, our brains utilize sleep time to “remove waste products,” that build up while we’re awake. Researchers at the University of Rochester Medical Center studying the brains of mice found that a waste-draining process, called the “glymphatic system,” is ten times more active during sleep. The nocturnal cleaning system is crucial to our health, ridding our brains of toxins that can eventually lead to conditions like Alzheimer’s. “It’s almost like opening and closing a faucet—it’s that dramatic,” says Dr. Maiken Nedergaard, one of the leading scientists on the study.
“The conservation of sleep across all animal species suggests that sleep serves a vital function. We here report that sleep has a critical function in ensuring metabolic homeostasis. Using real-time assessments of tetramethylammonium diffusion and two-photon imaging in live mice, we show that natural sleep or anesthesia are associated with a 60% increase in the interstitial space, resulting in a striking increase in convective exchange of cerebrospinal fluid with interstitial fluid. In turn, convective fluxes of interstitial fluid increased the rate of β-amyloid clearance during sleep. Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.”