U.S. medical scientists said they might have discovered the mechanism responsible for memory loss observed in Alzheimer's disease.

Researchers at the University of California-San Francisco's Gladstone Institute and the Baylor College of Medicine discovered a mechanism by which the protein Amyloid-beta might impair neurological functions in Alzheimer's disease.

Amyloid-beta, known to accumulate in the brains of Alzheimer patients, has long been a focus of research into the causes and treatment of the disease. In the new study, Gladstone scientists found A-beta triggers abnormal over-excitation of the same brain networks that are responsible for learning and memory.

"Such abnormal network activity in Alzheimer's patients was thought to be a collateral or secondary event caused by the degeneration of nerve cells," said Jorge Palop, a Gladstone research scientist and lead author of the study. "But our study suggests that this activity may actually be a primary effect of A-beta and an early determinant of cognitive failure."

The findings are detailed in the journal Neuron.