Study shows the aging brain has trouble generating brain waves required for deep sleep

Apr 6 2017

Older people tend to experience less sleep, due to taking frequent trips to the bathroom, and  losing the ability to create deep restorative sleep compared with young adults.

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In an article published in the journal Neuron on April 5^th, researchers from University of California, Berkeley, argued that elderly people are at an increased risk of memory loss and a wide range of mental and physical disorders when their sleep requirements are not met.

The senior author of the article and a UC Berkeley professor of psychology and neuroscience, Matthew Walker, said:

Nearly every disease killing us in later life has a causal link to lack of sleep. We’ve done a good job of extending life span, but a poor job of extending our health span. We now see sleep, and improving sleep, as a new pathway for helping remedy that.”

He further said that in contrast to physical markers of aging, such as wrinkles and gray hair, decline in sleep is linked to conditions such as Alzheimer’s, heart disease, obesity, diabetes, and stroke.

However, older people do not notice and report mental fogginess and other symptoms of inadequate sleep, unlike younger individuals.

Changes in sleeping patterns can begin from the early 30s and pave the way for sleep-related cognitive and physical ailments in later adulthood.

Although sleeping aids can be harvested from pharmaceuticals, Walker commented that sedation is not real sleep. He cautioned that medicinal drugs designed to help us sleep are poor alternates for the natural sleep cycle that the brain needs in order to function properly.

Walker and his research colleague Bryce Mander and Joseph Winer, support their research with previous studies which show that the aging brain has difficulties generating slow brain waves that promote deep sleep, and neurochemicals that help in the sleep-wake cycle.

The parts of the brain deteriorating earliest are the same regions that give us deep sleep”

Bryce Mander, postdoctoral researcher in Walker’s Sleep and Neuroimaging Laboratory at UC Berkeley.

Aging reduces deep non-rapid eye movement (NREM) and therefore brain waves associated with it.

Youthful and healthy slow waves and spindles shift memories and information from the hippocampus, which is mainly associated with short-term memory. This part of the hippocampus sends outputs to the prefrontal cortex, which accumulates the information and forms the brain’s long-term memory storage.

Joseph Winer, a doctoral student in Walker’s lab said:

Sadly, both these types of sleep brain waves diminish markedly as we grow old, and we are now discovering that this sleep decline is related to memory decline in later life.”

According to Mander, another deficiency in older people is the lack of the ability to regulate galanin and orexin, neurochemicals that promote sleep stability. A disturbance to the sleep-wake pace generally makes older people tired during the day and restless at night.

He  also added, a not all are vulnerable to sleep changes in their old age, and just as some age more successfully than others, some old people get better sleep than others, which however, is another line of study to be explored in the future work.

Interventions that are non-pharmaceutical in nature such as electrical stimulations are being looked at to enhance the sleep quality, in the context of aging.owever, the challenge lies in promoting alternatives to prescription and over-the-counter sleep aids.

Walker also commented, “The American College of Physicians has acknowledged that sleeping pills should not be the first-line kneejerk response to sleep problems.Sleeping pills sedate the brain, rather than help it sleep naturally. We must find better treatments for restoring healthy sleep in older adults, and that is now one of our dedicated research missions.”

It is also mentioned that the length of time slept does not always reflect a sufficient sleep - both quantity and quality of sleep are needed in order to achieve full restoration in brain processes.