A new wearable device has enabled scientists to monitor the brain’s waste-removal system in real time during sleep — a discovery that could pave the way for preventing Alzheimer’s and similar disorders.
Key Points at a Glance
- Scientists have tracked glymphatic system activity in sleeping humans using a wearable cap.
- The brain’s waste-removal system accelerates throughout sleep and slows upon waking.
- Findings may lead to therapies that improve glymphatic function and prevent neurodegeneration.
- This is the first non-invasive, real-time monitoring of the glymphatic system during natural sleep.
For the first time, researchers have watched in real time how the brain clears away waste while we sleep — thanks to a novel wearable device that could ultimately help stave off diseases like Alzheimer’s and Parkinson’s.
Published in Nature Biomedical Engineering, the study reports on a head cap embedded with electrodes that detects shifts in brain fluids, electrical activity from sleep to wakefulness, and changes in blood vessels. These measurements allow researchers to monitor the glymphatic system — the brain’s built-in cleansing network — as it operates overnight.
“We’ve long suspected that sleep is crucial for clearing toxins from the brain, but now we can actually watch that process unfold in real time,” said Jeffrey Iliff, professor of psychiatry and neurology at the University of Washington School of Medicine and coauthor of the study.
The study’s results upend the conventional belief that the glymphatic system only operates during deep sleep. Instead, researchers observed that the system remains active not only in slow-wave sleep, but also during REM sleep and into the waking process. Rather than functioning like a simple on-off switch, the system gradually ramps up the longer sleep continues, then winds down upon waking.
This fluid clearance system is essential for removing brain proteins such as amyloid-beta and tau — substances whose abnormal buildup has been directly linked to neurodegenerative diseases.
“Understanding how the glymphatic system behaves in natural sleep is a critical step,” said Iliff. “It opens the door to developing therapeutics that improve brain clearance, which may help prevent or treat Alzheimer’s and other neurological conditions.”
The research was carried out by a team from UW Medicine and the University of Florida, involving 49 participants aged 56 to 66. The study marked the first time these processes were tracked outside of an MRI machine, making it feasible to observe subtle changes during different sleep stages in a natural setting.
The wearable monitoring system was developed by Applied Cognition, a California-based biotech company. According to its CEO, Dr. Paul Dagum, the technology has already identified a promising drug candidate that enhances glymphatic clearance in early trials.
The implications are profound. The ability to non-invasively track glymphatic activity could lead to earlier diagnosis of neurological conditions, enable personalized treatments, and guide the development of new medications that target this system directly.
“This work is pivotal in defining the role glymphatic dysfunction plays in Alzheimer’s and discovering therapies to rescue it,” Dagum said.
Iliff’s lab continues to explore the glymphatic system’s role in disorders ranging from Alzheimer’s to traumatic brain injury. The integration of wearable tech into this research marks a critical step forward — offering a scalable, non-invasive path to better brain health for millions.
Source: University of Washington
