AdvertisementHow Deep Sleep May Help The Brain Clear Alzheimer's ToxinsOctober 31, 2019Jon HamiltonfacebookEmailDuring deep sleep, waves of cerebrospinal fluid (blue) coincide with temporary decreases in blood flow (red). Less blood in the brain means more room for the fluid to carry away toxins, including those associated with Alzheimer's disease. (Fultz et al. 2019)