Reduced blood flow to the brain is thought to be a key factor in many forms of dementia, including Alzheimer’s, and scientists have just identified a new mechanism regulating this flow, which may also help explain how it goes wrong.

A fat molecule helps maintain the system’s balance, researchers at the University of Vermont discovered, and in mouse models of Alzheimer’s disease, disruption of this balance led to problems.

Fixing the imbalance restored more normal blood flow, offering a hopeful new target for understanding and treating dementia-related brain changes.