Media

Poor sleep among older adults is linked to disruptions in the brain’s “waste removal system”, according to researchers at The University of Hong Kong (HKU).  A recent study led by Professor Tatia M.C. Lee, Chair Professor of Psychological Science and Clinical Psychology and May Professor in Neuropsychology at HKU, offers valuable insight into how sleep quality impacts brain functioning.

Many studies have linked poor sleep with a decline in brain functioning. Professor Lee’s team focused on the glial-lymphatic (glymphatic) system, a fluid transport pathway that plays a vital role in clearing waste from the brain. The system’s efficiency is a critical determinant of brain health, particularly in ageing populations.

Professor Lee and her team sought to understand the glymphatic-brain relationship in poor sleepers, which underlies memory decline. Dysfunction of the glymphatic system leads to the accumulation of toxic proteins, and this process has recently been implicated in several neurological disorders, such as Alzheimer’s disease, Parkinson’s disease and epilepsy.

“Sleep quality, brain activities, and glyphamtic functioning are related. Understanding how sleep quality influences the glymphatic system and human brain networks offers valuable insight into the neurophysiological mechanisms underpinning age-related memory change,” Professor Lee said.

The research team studied 72 older adults using functional MRI scans and sleep recordings.  The findings indicate that poor sleep quality adversely affects normal brain function by deactivating the restorative glymphatic system. “The results clearly reveal the effect of sleep on the human brain’s network through the glymphatic system, which in turn affects memory performance in older adults,” said Professor Lee. “Therefore, maintaining efficient glymphatic functioning seems crucial for promoting healthy ageing.”

The results of the study add important evidence that sleep quality affects cognitive health through the underlying neural relationships. “Impaired memory is a common complaint among older adults with poor sleep quality,” Professor Lee noted. “Our results provide a novel perspective on the interplay between sleep, the glymphatic system and multimodal brain networks.”

This study was recently published in Molecular Psychiatry in an article entitled “Effects of sleep on the glymphatic functioning and multimodal human brain network affecting memory in older adults”.

Link to the paper: https://www.nature.com/articles/s41380-024-02778-0

Media enquiries:
Miss Alice Wong, Faculty of Social Sciences, HKU (Tel: 3917 1230; Email: sklbrain@hku.hk)