Biomarker of Alzheimer's found to be regulated by sleep cycles Immune cells known as microglia (turquoise with red dots) surrounding amyloid plaques Brian Lananna Brian Lananna Scientists at Washington University School of Medicine (WUSM) in St. Louis have spent some years investigating the links between circadian rhythm and Alzheimer’s, and have recently been making some real inroads. Following a 2018 study demonstrating how disrupted sleep can accelerate the buildup of toxic plaques associated with the disease, the team has now identified a protein implicated in the progression of the disease that appears highly regulated by the circadian rhythm, helping them join the dots and providing a potential new therapeutic target.