It’s an inconvenient truth of aging: In our 30s and up, it gets increasingly harder for most of us to recall names, faces, and details from the past. Scientists have long debated whether this gradual decline is an early form of Alzheimer’s disease—a neurodegenerative condition that leads to severe dementia—or a distinct neurological process. Now, researchers have found a protein that distinguishes typical forgetfulness from Alzheimer’s and could lead to potential treatments for age-related memory loss. Previous studies have shown that Alzheimer’s disease and age-related memory loss involve different neural circuits in the hippocampus, a seahorse-shaped structure in the brain...