Abstract

This manuscript-based thesis explores the relationships between sleep and sleep physiology during non-rapid eye-movement (NREM) sleep stages 2 and 3, brain-health, and cognition in older adults and persons with Alzheimer’s Disease (AD). It provides new insights into the associations between sleep, biomarkers of neurodegeneration, and cognition in older adults. It also provides new evidence demonstrating that spindle and slow oscillation activity during NREM sleep constitute predictive and non-invasive biomarkers of neurodegeneration, cognition, and mental health in persons with AD. Sleep microarchitecture can, therefore, also provide novel therapeutic targets for preserving brain-heath and slowing AD progression. These findings extend previous evidence showing that sleep may be one of the most important modifiable risk factors for functional and cognitive decline and dementia in older adults. The thesis then explores how exercise, a promising and widely accessible intervention targeting sleep physiology, can be an effective intervention for poor sleep in healthy older adults and persons with Mild Cognitive Impairment and AD. The implications of this thesis’ findings for clinical care of persons with AD, preserving brain-health and cognition in older adults, and sleep research are discussed. Our findings can serve as a springboard for future research on sleep-based strategies to preserve brain health in older adults and delay the progression of AD symptoms, with considerable potential benefits for persons with AD, their caregivers, and communities.