Sleep Deprivation Linked to Alzheimer’s Disease
Scientists already know lack of sleep raises the level of beta-amyloid — a protein connected with Alzheimer’s disease — in mice. Now, they have determined that the loss of a single night of sleep rapidly increases beta-amyloid in humans as well.
The findings suggest sleep could aid beta-amyloid clearance.
Beta-amyloid forms amyloid plaques, which impede communication between neurons. Researchers used PET scans to study the brains of 20 healthy participants, ages 22 to 72. Beta-amyloid levels rose approximately 5 percent in the hippocampus and thalamus after subjects lost a night of sleep. Compared with those in healthy older adults, beta-amyloid levels in people who have Alzheimer’s disease rise by about 43 percent.
Nearly 6 million Americans have Alzheimer’s, according to the Alzheimer’s Association.
The study is online in the Proceedings of the National Academy of Sciences.
Marker May Aid Brain Disease Research
The development of a marker substance that makes N-methyl-D-aspartate (NMDA) receptors visible could enhance research on a range of debilitating brain diseases, according to Swiss and German scientists.
The marker, called a PET tracer, should allow researchers to view the receptors on the surface of nerve cells. It has been tested only in rats but is slated for use in clinical trials investigating the therapeutic possibilities of NMDA candidate drugs as well as the role NMDA receptors play in conditions such as Parkinson’s and Alzheimer’s.
The researchers — from ETH Zurich, University Hospital Zurich and the University of Münster — say the PET tracer may prove especially valuable in determining correct dosages of drugs related to NMDA receptor activity.
The study appears in the Journal of Nuclear Medicine.
Education vs. Dementia
Dementia risk is lower for older Americans who have a college education, a study led by researchers at the University of Southern California has found.
The study examined approximately 10,000 participants in 2000 and 2010 who were age 65 or older. Interviewer observations and a series of questions were used to assess cognitive status. The education-level categories consisted of people who had a college degree or more, those with some college education, those with a high school diploma and those who did not finish high school.
Between 2000 and 2010, life expectancy with a strong level of cognition rose by about 1.5 years and 1.8 years, respectively, for men and women 65 or older who had a college degree. It rose only 0.66 years and 0.27 years, respectively, for men and women with the least education.
The findings appear in a dementia-related supplement to The Journals of Gerontology, Series B: Psychological Sciences and Social Sciences.