Departments: News, Notes and Tips
Those frequent sleepless nights nursing students and faculty frequently experience may be doing more than making us tired the following day. Researchers from Stanford and Washington University have recently determined that sleep deprivation and disturbed sleep cycles contribute to the development of amyloid-β (Aβ) in the extracellular fluid of the brain. This protein becomes the amyloid plaque we know as a hallmark for Alzheimer's disease.
Aβ is produced by neurons and deposited in the interstitial fluid of the brain (ISF), and converts to a damaging form as the concentration increases. Kang et al1 monitored changes in Aβ levels by inserting microdialysis probes in experimental mice. ISF Aβ levels were negatively correlated with the amount of time the mice slept and increased when the mice were awake. ISF Aβ levels were significantly higher during times of forced wakefulness. Following sleep deprivation the mice slept longer when allowed to do so and ISF Aβ levels decreased. Mice subjected to 20 hours of sleep deprivation for 21 days showed much higher levels of Aβ plaque deposition than their age-matched litter mate controls.
Sleep disturbances are known to be associated with various neurodegenerative diseases1 and now shown to be associated with the changes that contribute to Alzheimer's disease. Perhaps further understanding of the physiology of sleep and ways to optimize sleep could inhibit accumulation of Aβ plaque. This could thus slow the development and progression of Alzheimer's disease. Meanwhile, remember that a good night's sleep is better for your health than you ever before imagined.
Source: Science CiteTrack: This Week In Science. November 12, 2009. Sleep and Alzheimer's Disease. Available athttp://www.sciencemag.org/content/vol326/issue5955/twis.dtl#326/5955/915-f.Accessed November 14, 2009.
Submitted by: Robin Pattillo, PhD, RN, News Editor atNENewsEditor@gmail.com.
1. Kang J, Lim M, Bateman RJ, Lee J, Smyth L, Cirrito J, Fujiki N, Nishino S, Holtzman D. Amyloid-β Dynamics Are Regulated by Orexin and the Sleep-Wake Cycle. Science
. 2009;326(5955):1005-1007. DOI: 10.1126/science.1180962.