Lulu Xie et al. – Science, 342-373 (2013)
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 b-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.
Università di Tor Vergata