Alzheimer's Disease and Sleep-Wake Disturbances: Amyloid, Astrocytes, and Animal Models.

Sleep-wake abnormalities are common in patients with Alzheimer's disease, and can be a major reason for institutionalization. However, an emerging concept is that these sleep-wake disturbances are part of the causal pathway accelerating the neurodegenerative process. Recently, new findings have provided intriguing evidence for a positive feedback loop between sleep-wake dysfunction and ß-amyloid (Aß) aggregation. Studies in both humans and animal models have shown that extended periods of wakefulness increase Aß levels and aggregation, and accumulation of Aß causes fragmentation of sleep. This perspective is aimed at presenting evidence supporting causal links between sleep-wake dysfunction and aggregation of Aß peptide in Alzheimer's disease, and explores the role of astrocytes, a specialized type of glial cell, in this context underlying Alzheimer's disease pathology. The utility of current animal models and the unexplored potential of alternative animal models for testing mechanisms involved in the reciprocal relationship between sleep disruption and Aß are also discussed.Dual Perspectives Companion Paper: Microglia-Mediated Synapse Loss in Alzheimer's Disease by Lawrence Rajendran and Rosa Paolicelli.