Study Shows Link Between Lack of Deep Sleep and Brain Deterioration

In a study just published in the journal Nature Neuroscience, scientists at the University of California, Berkeley, show a connection between decreased slow brain waves generated during deep sleep and memory loss/brain deterioration as we grow older. This evidence that slow waves in the frontal brain help strengthen memories gives hope to therapeutic treatments for memory loss in the elderly.

The senior author of the study, UC Berkeley sleep researcher and associate professor of psychology and neuroscience, Matthew Walker, summed it up by saying "What we have discovered is a dysfunctional pathway that helps explain the relationship between brain deterioration, sleep disruption and memory loss as we get older -- and with that, a potentially new treatment avenue.”

Non-rapid-eye-movement (REM) or deep sleep usually accounts for one-quarter of a healthy adults’ night sleep. During this time, slow waves are generated by the middle frontal lobe. These restorative slow waves influence how memories go from the hippocampus, where memories are stored temporarily, to the prefrontal cortex for long-term storage. The study finds that deterioration of this frontal region of the brain (called Medial prefrontal cortex gray-matter atrophy) in elderly people is linked to their failure to generate sufficient deep sleep. Lack of sleep compromises pathways between the hippocampus and the prefrontal cortex leaving memories susceptible to being “overwritten” and unable to be stored long-term.

Researchers at UC Berkeley will be conducting sleep-enhancement studies in older adults to determine if increased REM can enhance memory and prevent brain deterioration as a result of aging. "Can you jump start slow wave sleep and help people remember their lives and memories better? It's an exciting possibility," said Bryce Mander, a postdoctoral fellow in psychology at UC Berkeley and author of this latest study.

This exciting research suggests that we are moving closer to understanding ways to avoid maladies of aging such as dementia and alzheimer’s. Alzheimer’s disease is not a normal part of the aging process and accounts for 50-80% of dementia cases. Getting 7-8 hours of uninterrupted sleep a night is one of the Alzheimer’s Association’s six pillars of a brain healthy lifestyle. Evidence in studies like this suggest that preventative measures can be taken to reduce the chances, stave off the disease or increase quality of life of those already afflicted.