2022 Alzheimer's Association Research Fellowship (AARF)

Aberrant Light Exposure, Chronodisruption and Alzheimer’s Disease

How might abnormal light exposure impact the onset and progression of Alzheimer’s disease?

Benjamin Weger, Ph.D.
University of Queensland
Brisbane, Australia

Background

Circadian rhythms are natural biological changes that occur over an approximately twenty-four-hour cycle and are often called the sleep-wake cycle. These rhythms usually respond to the amount of light and darkness in an environment. They involve daily patterns of sleeping, eating and other activities. Disruptions to circadian rhythms can alter an individual's ability to get proper sleep. More than 50% of individuals with dementia experience sleep disruptions or poor sleep patterns that precede cognitive impairment by several years. 

Disruptions to circadian rhythms may not only be a consequence of Alzheimer’s progression, but also an active driver of it. Recent studies reveal that sleep disruption, either from not enough exposure to bright light during the day or by night-time light exposure, may impact the risk of developing Alzheimer’s and other brain diseases. However, the biological mechanisms underlying the relationship between circadian rhythm disruption due to abnormal light exposure and Alzheimer’s progression remains unknown.

Research Plan

Dr. Benjamin Weger and colleagues will study the mechanisms and identify biological markers to better understand the links between abnormal light exposure, circadian rhythm disruption, and Alzheimer’s. Using genetically engineered Alzheimer’s-like mice, the researchers will investigate whether abnormal light exposure (low light during the day and late night-time light) impacts the onset and progression of deficits in memory and other areas of cognition. They will analyze brain tissue collected at different time points and will also investigate how circadian rhythm disruption may impact gene activity in brain areas affected by Alzheimer’s.

Lastly, the researchers will study blood samples and brain tissue from genetically engineered Alzheimer’s-like mice, focusing on biological markers of brain inflammation and other brain pathways involved in Alzheimer’s progression.

Impact

The study results may provide insights into the biology associated with sleep-wake disturbances in early Alzheimer’s. If successful, the findings may suggest a role for light exposure in the onset and progression of Alzheimer’s.