Insufficient deep sleep could lead to Alzheimer’s

NOT getting enough deep sleep could set the stage for Alzheimer’s, according to a Jan. 4 report from National Public Radio (NPR).

During sleep in animals, the brain seems to purge toxins linked to Alzheimer’s, brain scientist Jeffrey Iliff from Oregon Health & Science University (OHSU) in Portland told NPR. But for sleep-deprived animals, toxins can accumulate and have a negative impact on the brain.

The toxin-cleansing process, known as the glymphatic system, functions primarily while an individual sleeps and is largely disengaged while one is awake, according to the National Center for Biotechnology Information.

“The biological need for sleep across all species may therefore reflect that the brain must enter a state of activity that enables elimination of potentially neurotoxic waste, including -amyloid,” according to a 2015 study in the journal Neurochemical Research. -amyloid, or amyloid-beta, is also linked to Alzheimer’s.

Iliff and other researchers from OHSU will soon begin a study on people that should explain the connection between sleep problems and Alzheimer’s in humans.

Sleep disorders are common in individuals with Alzheimer’s. Scientists have long thought this was because the disease was “taking out the centers of the brain that are responsible for regulating sleep,” Iliff told NPR. However, two studies in 2009 and 2013 have suggested a more complex relationship.

In 2009, researchers at Washington University in St. Louis demonstrated that a buildup of sticky amyloid plaques linked to Alzheimer’s developed more quickly in the brains of sleep-deprived mice. These plaques are also known to develop in people’s brain tissue as they age.

Four years later, a team that included Iliff found that a cleansing process occurs in the brains of animals during deep sleep.

Studying the link between sleep deprivation and Alzheimer’s in humans will be more challenging than in mice. NPR reported that a signal indicating toxin removal during sleep is expected to be stronger in younger individuals than in older people, said Bill Rooney, director of OHSU’s Advanced Imaging Research Center, who will be involved in research process set to begin within one year.