Via EurekAlert!: researchers have "revealed a previously unknown mechanism that may drive the early brain function deterioration of Alzheimer's victims, thus opening a new exploratory path in the quest for an Alzheimer's cure. ... Researchers have known for years that a substance called amyloid-beta gums up brain cells when it becomes too concentrated, because it forms damaging deposits on the cells known as plaques. These prevent normal electrical signal generation in the cells, eventually killing them. That drives the memory loss and other problems that plague Alzheimer's sufferers. Most Alzheimer's studies have focused on brain cells already damaged by amyloid-beta or the effects of high concentration of amyloid-beta. [This study] instead explored impacts of very low amyloid-beta concentrations on healthy cells in an effort to mimic the earlier stages of Alzheimer's. ... though there are no outward signs of damage, exposure to moderate amyloid-beta concentrations somehow prevents electrical signals from traveling normally through the cells. Because the effect is seen in otherwise healthy cells, [researchers believe] the team may have uncovered a critical process in the progression of Alzheimer's that could occur before a person shows any known signs of brain impairment."