A new study challenges the long-standing view that Alzheimer’s is driven primarily by amyloid plaques, instead pointing to a subtle but critical competition inside neurons.

New research led by the University of California, Riverside, suggests Alzheimer’s disease may not be driven solely by plaque buildup in the brain, as widely believed. Instead, it may result from one protein disrupting the normal function of another.

For years, scientists have focused on amyloid beta (a-beta) as the main cause of Alzheimer’s. Clusters of this protein are commonly found in patients, and genetic mutations that raise a-beta levels are known to trigger early-onset Alzheimer’s.