Further research on the importance of sleep to glymphatic clearance was published in October 2013 by Maiken Nedergaard et al, the team involved in the original discovery of the glymphatic pathway. The more recent work shows that the clearance of brain metabolites is most efficient during sleep.
It is hoped this new understanding of the importance of sleep may pave the way for new treatments for Alzheimer’s, Parkinson’s and other diseases of the brain caused by the build up of neurotoxic metabolites, such as Amyloid β.
The glymphatic system is formed by glial cells creating tubes around blood vessels in the brain, and the new research (in mice) showed that the calibre of these drainage pathways enlarged up to 60% during sleep, compared with when the mice were kept awake.
Here is a short video from the University of Rochester where the research is being carried out:
In particular, beta amyloid protein which is known to form damaging plaques in Alzheimer’s disease, was shown to be excreted from the brain twice as quickly during sleep.
So it seems that sleep is absolutely essential to long-term neurological health, as well as its day-to-day housekeeping.
More in the video below.
Sleep Drives Metabolite Clearance from the Adult Brain
Lulu Xie, Hongyi Kang, Qiwu Xu, Michael J. Chen, Yonghong Liao, Meenakshisundaram Thiyagarajan, John O’Donnell, Daniel J. Christensen, Charles Nicholson, Jeffrey J. Iliff, Takahiro Takano, Rashid Deane, and Maiken Nedergaard
Science 18 October 2013: 342 (6156), 373-377. [DOI:10.1126/science.1241224]