Scientists have taken an important step toward understanding one of the most puzzling features of Alzheimer’s disease. In some older people, autopsies find the classic signs of the illness — amyloid plaques and tau tangles, that is, clusters of toxic proteins. Yet during life, they showed no noticeable problems with memory or thinking. Researchers estimate that such cases may account for up to 30%. This condition is called “asymptomatic Alzheimer’s.”
Scientists from the University of California, San Diego and Weill Cornell Medicine used artificial intelligence to analyze data from thousands of human brain samples. The algorithm identified a “genetic signature” of the disease — 40 genes whose activity distinguishes an affected brain from a healthy one. The signature was then tested across different lines of laboratory mice.
AI helped find a unique model: the mice had molecular signs of Alzheimer’s, yet retained the ability to learn and remember. A key role was played by the protein chromogranin A (CgA), which is linked to the function of nerve cells. When it was switched off, males retained normal memory even when the brain tissue showed signs of the disease. In females, the effect was even stronger: they had fewer tau tangles and better-preserved connections between neurons. In humans, Alzheimer’s disease also affects men and women differently. Women are more often diagnosed with it, but in the early stages they can sometimes maintain cognitive function for longer.
Of course, this is not a cure yet. The work is still at the preclinical stage and has been carried out in animals. But the direction looks very promising. For a long time, the main strategy in the fight against Alzheimer’s was to try to remove pathological proteins from the brain. Now the focus is gradually expanding: scientists want to understand why the brain can sometimes live with damage — and whether that resilience can be strengthened in others.
