Scientists from Johns Hopkins Medicine report new evidence that clusters of brain tissue derived from the cells of patients with Alzheimer’s disease may be used to evaluate how certain patients with the neurodegenerative condition may respond to drugs commonly prescribed to treat psychiatric symptoms of the disorder. The findings, based on a study of lab-grown brain tissues known as organoids, contribute to a growing body of evidence that brain organoids may also one day be used to more precisely develop and prescribe treatments for subgroups of patients with Alzheimer’s disease, which is the most common form of dementia, and affects more than seven million Americans.

In addition, the researchers found that tiny particles, known as extracellular vesicles, which are secreted by organoids, may contain cellular information that could help scientists find new biomarkers to diagnose and stage Alzheimer’s disease. A report of the findings is published in Alzheimer’s & Dementia.

“Our study suggests that large-scale, patient-derived brain organoids and the vesicles they secrete can help us stage Alzheimer’s disease, investigate the mechanisms that drive it and assess how patient subgroups may respond to different treatments,” says study leader Vasiliki Machairaki, Ph.D., associate professor of genetic medicine at the Johns Hopkins University School of Medicine.