Scientists discovered it inside the human spinal fluid

Sep 27, 2011 13:42 GMT  ·  By

Experts with the Washington University in St. Louis School of Medicine (WUSM) were recently able to identify a new marker for Alzheimer's disease. The interesting thing about it is that it soars and dips inside the spinal fluid in patterns eerily similar to the body's sleep cycle.

This daily repetition of the patterns got researchers interested in these signals. One of the things the group found most interesting is that the cyclic pattern appeared to decrease in strength as people got older. The signal was determined to be strongest in young people.

According to the WUSM team, these findings lend additional credence to an emerging theory that proposes the existence of a correlation between inadequate sleep patterns and the development of Alzheimer's disease. The condition is a neurodegenerative, lethal form of dementia.

At first, experts discovered this correlation in animal models, but failed to establish any such link in humans. The new data strongly suggest that maybe experts have been looking in the wrong direction all this time, PsychCentral reports.

The work was focused on studying the behavior of amyloid beta protein, a factor long-since known to play a role in underlying the disorder. These molecules have a tendency to be produced in high amounts, and then agglomerate in the brain.

Firmly lodged between neurons, they create hardened structures called plaques that do not let anything pass through. Amyloid concentrations have been used as a proxy for detecting Alzheimer's for quite some time now.

What the WUSM group is suggesting is that losing sleep, or sleeping at irregular intervals, makes it harder for the body to dispose of the excess amyloid concentrations, therefore opening the way for it to accumulate in the brain.

The brain is perfectly capable of clearing the entrenched protein, but it needs to have a brake in order to do this. Experts believe that sleep naturally supplies such a time-off period. But tampering with it can lead to the brain losing its clean-up abilities, and becoming overrun with amyloid.

“In healthy people, levels of amyloid beta drop to their lowest point about six hours after sleep, and return to their highest point six hours after maximum wakefulness,” explains WUSM associate professor of neurology Randall Bateman, MD.

“We looked at many different behaviors, and the transitions between sleep and wakefulness were the only phenomena that strongly correlated with the rise and fall of amyloid beta in the spinal fluid,” he concludes.