Scientists have identified a molecular switch that may explain why the ageing brain becomes more vulnerable to neurodegenerative diseases such as ALS and Huntingtons. In worms, researchers found that the protein EPS8 accumulates with age, activating signaling pathways that promote the clumping of toxic proteins. These harmful aggregates damage neurons and shorten lifespan. However, reducing EPS8 activity prevented protein buildup, protected nerve function, and helped preserve healthy ageing.