Memory Loss May Not Be the Earliest Sign of Alzheimer’s
Nautilus · 2026-07-03
Neuroscientists at Texas A&M University have found that a decline in cognitive flexibility may precede memory loss in Alzheimer's disease, suggesting it could be an earlier diagnostic indicator. Using 5xFAD mice, genetically engineered to develop amyloid-beta plaques, researchers tested their ability to adapt to changed reward contingencies after being conditioned to a specific task. Healthy mice adjusted readily, while the 5xFAD mice demonstrated significant impairment in switching strategies, persistently repeating previous, unrewarded actions. When researchers chemically quieted overactive neurons in the 5xFAD mice, they observed reduced amyloid-beta accumulation, normalized neural activity, and improved cognitive flexibility, with benefits proving long-lasting. While these findings require human confirmation, the research team is optimistic that assessing cognitive flexibility could enable earlier Alzheimer’s diagnoses, crucial for effective treatment given the disease's progressive neuronal degeneration.
*The full article also explores the specific mechanisms by which calming neuronal hyperactivity impacts amyloid-beta pathology and cognitive function.*