Impact of Alzheimer’s on Daily Rhythms in the Brain

A team of researchers from the Washington University School of Medicine in St. Louis has demonstrated that Alzheimer’s disease disrupts the daily rhythms within certain brain cells. This disruption affects how and when hundreds of genes are turned on and off, altering fundamental processes that help the brain function properly.

Study on Alzheimer’s Effect on Daily Rhythms

The findings of this study were published in the journal Nature Neuroscience on October 23. They suggest that restoring or stabilizing these internal rhythms could open new avenues for treating Alzheimer’s disease. The research shows that 82 genes are associated with the risk of developing Alzheimer’s, and daily rhythms control the activity of about half of these genes. In mouse models designed to mimic the disease, these genes did not follow their usual daily patterns.

This discovery provides researchers with an opportunity to explore therapeutic methods to manipulate these genes and prevent the progression of the disease. Additionally, sleep disturbances are among the most common issues reported by caregivers of Alzheimer’s patients, and previous research has shown that these sleep changes begin years before memory loss appears.

Functions of Daily Rhythms in the Brain

Daily rhythms help regulate about 20% of all genes in the human genome, coordinating vital processes such as digestion, immune response, and sleep-wake cycles. An excess of the protein YKL-40, linked to Alzheimer’s risk in humans, can lead to the accumulation of amyloid, a sticky protein that forms plaques, one of the disease’s hallmark features.

The team believes that Alzheimer’s symptoms following a repetitive daily pattern may be linked to more proteins and genetic patterns regulated by daily rhythms. In the study, the gene activity was examined in the brains of mice that developed amyloid accumulations, as well as in young healthy mice and older mice without plaques.

Genetic and Protein Effects

Researchers found that amyloid accumulations disrupt the natural rhythm of hundreds of genes in two main types of brain cells—microglia and astrocytes. Microglia act as immune cells for the brain, while astrocytes aid in communication between neurons and maintain their healthy function.

Although these genes were not completely turned off, their usual order and timing became chaotic, weakening the brain’s coordinated system for detoxification. Amyloid plaques appeared to create new rhythmic patterns in genes not accustomed to following a daily cycle.

Potential Treatments and Interventions

These findings suggest that treatments aimed at modifying daily rhythms in microglia and astrocytes could support healthy brain activity. Researchers are exploring how to enhance the rhythmic system to prevent amyloid accumulation and other aspects of Alzheimer’s disease.

Dr. Erik S. Musiek notes that the goal is to manipulate the biological clock in some way, making it stronger or weaker or stopping it in specific cell types, with the ultimate hope of improving the rhythmic system to prevent amyloid accumulation and other disease aspects.

Conclusion

The study underscores the importance of a deep understanding of the connection between daily rhythms and Alzheimer’s disease. It shows that manipulating these rhythms can have a positive impact on mental health and prevent disease progression. The hope for the future lies in developing treatments that target the biological clock to enhance mental and functional brain health.