PHILADELPHIA -- Opening a new front in the battle against Alzheimer's disease, scientists at the University of Pennsylvania have found that a protein long associated with the disease inflicts grave damage in a previously unimagined way: It seals off mitochondria in affected neurons, resulting in an "energy crisis" and buildup of toxins that causes cells to die. This pathway, the first specific biochemical explanation for pathologies associated with Alzheimer's, is detailed in the April 14 issue of the Journal of Cell Biology.