Coupling of neural oscillations in sleep, in relation to cognition, aging, and Alzheimer’s disease

Sleep fulfills important adaptive functions, including maintaining bodily homeostasis, and rejuvenating immune function, contributing to health and modulating risk of morbidity. Sleep is also associated with improved cognitive functioning. Poor sleep is common among aging populations, and often manifests as, for example, poor sleep maintenance (e.g., frequent arousals from sleep), altered sleep-wake rhythms, and reduced time spent in slow wave sleep. Aberrant brain oscillation activity during sleep, such as reduced slow wave oscillation amplitudes or fewer sleep spindles, is associated with poor sleep and with cognitive impairments across the lifespan. Brain oscillations can be measured across brain regions using electroencephalography (EEG) and are examined within specific frequency bandwidths.

Analytic developments in neuroscience have allowed researchers to quantify a phenomenon of brain oscillation “coupling,” wherein oscillations with distinct frequency characteristics synchronize with each other, both within and across brain regions. This coupling, observed in both awake and asleep EEG data, is thought of as a potential mechanism through which the brain transfers information and consolidates memories. A growing theory suggests that age-related declines in oscillation coupling may be implicated in the pathophysiology of age-related cognitive impairments, and perhaps also dementia, such as Alzheimer’s disease (AD). However, there is a paucity of studies examining relations between brain oscillation coupling during sleep and aging-related cognitive impairments or neurodegenerative diseases like AD, especially in humans. In turn, this research examines associations between coupling of distinct brain oscillations during sleep and overnight memory consolidation in healthy younger and older adults, and in older adults with mild cognitive impairments and AD. The overarching goal of this research is to better understand neurological phenomena underlying memory consolidation processes, and to elucidate possible mechanisms underlying relations between sleep and AD pathophysiology.

Researchers

• Thien Thanh Dang-Vu (Concordia University)
• Oren Weiner (Concordia University)
• Jordan O'Byrne (Concordia University)
• Despina Bolanis (Concordia University)
• Lukia Tarelli (Concordia University)
• Lea Homer (Concordia University)
• Victoria Yue (Concordia University)
• Katherine Walker (Concordia University)
• Roxanne Carbone (Concordia University)
• Katherine Chhuon (Concordia University)
• Kenza Eddebbarh (Concordia University)
• Julia Lumia (Concordia University)
• Dylan Smith (Concordia University)
• Nathan Cross (Concordia University)
• Melodee Mograss (Concordia University) 

Funding

• FRQS (Fonds de recherche du Québec)
• NSERC (Natural Sciences and Engineering Research Council of Canada)