The Woolcock Institute of Medical Research

Your memory not what it used to be? Your sleeping brain could be to blame, Australian researchers believe.

Scientists at the Woolcock Institute of Medical Research in Sydney are peering into the sleeping brains of older Australians to find new ways of stopping cognitive decline in its tracks, in new efforts to tackle the problem of dementia.

The unique research uses powerful neurotechnology to observe the brain throughout the night to find out which parts aren’t ‘sleeping well’, explains sleep specialist Dr Angela D’Rozario. “What your brain does when you sleep holds vital clues about the state of your cognitive thinking and your ability to form memories,” she says. “We believe we can link these problem areas of the sleeping brain with specific brain and memory issues, and ultimately develop new treatments that can slow or even halt the cognitive decline.” 

The Woolcock team are recruiting 40 older Australians aged 50-90, either with or without signs of mild cognitive impairment, to reveal secret links between brain wave behaviour and cognitive problems.

The work was inspired by recent landmark discoveries showing normal sleep clears out damaging “toxins” that build up in the brain during wakefulness.

“Sleep protects the brain from all the toxic by-products that build up while we’re awake by using the glymphatic system, which acts like the brain’s plumbing system, to clear out the accumulated waste,” the sleep expert explains. “This active process during sleep is thought to restore the efficiency of the brain cells and promote optimal functioning ready for the next day. If this process is disrupted either by lack of sleep or disturbed sleep through sleep disorders then toxins can build up and potentially cause brain injury.” 

The research team will use topographical analysis of brain wave activity using a neurotechnology called high-density EEG to watch these waves in great detail throughout the night. The high tech scan is able to sample from 256 cortical sites compared to the standard six during an overnight sleep study, offering up results far more sophisticated and detailed than previously seen.

Observing their volunteers, the researchers will work to pinpoint which areas in the brain have abnormal sleep and, using the results of an MRI scan, tie these to specific cognitive deficits. Recruits are invited back for a follow-up 1-2 years later to assess their cognitive trajectory over the longer term.  

Dr D’Rozario is excited by the study’s potential. “We know sleep is strongly linked to cognitive function but with this study we have the opportunity to understand the mechanisms that underlie this relationship in aging” she says. “In doing this we have the potential to target sleep with brand new treatments that, for instance, boost these sleep brain waves with drugs or devices like brain stimulation. If we pick the decline up early, we can target it and potentially delay or even stop dementia developing.”

The work is all the more important given Australia’s aging population and rising rates of dementia. “It’s predicted that a quarter of Australia’s population will be over the age of 65 by 2056,” Dr D’Rozario says. “Any findings that can help improve sleep in this huge population and ultimately slow cognitive decline would be enthusiastically welcomed.”

Those interested in joining the study should visit the Woolcock website (see “Exploring the links between poor sleep, memory impairment and cognitive decline”). Volunteers can have a diagnosis of mild cognitive impairment, or concerns about changes to their memory and thinking. Researchers also welcome participants with no cognitive concerns to act as controls for the study. You will be required to stay overnight at the Woolcock Sleep Lab in Glebe, and undergo an MRI scan as well as a range of cognition and memory tests. Recruits are compensated for time spent in the clinic.