Well-regulated sleep vital for functional glymphatic system

Key takeaways:

• Sleep is a vital, non-waking function of the body that impacts the glymphatic system.
• Failure of the glymphatic system due to a number of factors likely accelerates the path to dementia.

DENVER — For the glymphatic system of the brain to function properly, individuals must pay attention to their sleep duration, regulation and deprivation, according to a presenter at the American Academy of Neurology annual meeting.

“Sleep induces both acute and long-term changes in the brain,” said Maiken Nedergaard, MD, DMSc, a professor and researcher at the University of Rochester Medical Center. “Our hypothesis is that sleep must fulfill a function that’s simply not possible when we’re awake.”

Although the lymphatic system exists in the remainder of the human body and acts as both a drainage and recirculation system, it does not exist within the brain.

However, Nedergaard noted, the glymphatic system — which exists only within the brain — appears to act in a similar manner as a drainage system for cerebrospinal fluid that has been proposed to be a sink for waste such as tau proteins. This vital function can only occur, and occur at its maximum potential, when a person has good sleep duration and regulation.

Tau, along with other proteins that accumulate in the brain during the lifespan, has been linked to increased risk of dementia as individuals age. Likewise, issues with sleep duration, regulation and deprivation throughout the lifespan have been linked to the loss of dendrites in the locus coeruleus that play a part in accelerating the aging process, Nedergaard said.

In addition, Nedergaard said, failure of the glymphatic system due to aging and sleep quality or external factors such as genetic risk, stagnant lifestyle routines or substance use disorders, has a direct impact on the appearance and impact of neurodegeneration and neuroinflammation, which presage conditions such as dementia.

Knowledge of these internal mechanisms may lead clinicians on a path of intervention, given a proper platform; however, the need for sleep is non-negotiable, she added.

“Something as simple as giving a recommendation of taking sleep more seriously might help these patients delay dementia,” Nedergaard said.