Researchers at the University of California San Francisco report that lowering levels of a single protein, FTL1, can reverse key markers of brain aging in mice. The study, conducted by the Villeda Lab, found that FTL1 concentrations rise sharply in the hippocampus—the brain region critical for learning and memory—as mice grow older. When scientists used genetic techniques to suppress FTL1 in the hippocampi of aged mice, the animals regained synaptic density comparable to that of much younger counterparts. The treated mice also performed significantly better in established spatial-memory tasks, indicating a functional recovery rather than a cosmetic change in brain tissue. The team says the results position FTL1 as a promising therapeutic target for combating age-related cognitive decline. Further research will focus on determining whether similar mechanisms operate in humans and on developing safe methods to modulate FTL1 activity in the aging brain.