Researchers said that they may have discovered the molecular-level cause of Alzheimer’s disease. Scientists at the University of California—Riverside, in recent findings, said that the key to understanding Alzheimer’s may have to do with “tau” proteins that likely caused neurofibrillary tangles—which are found in the brains of Alzheimer’s patients. Previously, researchers have suggested that amyloid plaques, which are a buildup of amyloid peptides, may also be the cause. Both amyloid plaques and the neurofibrillary tangles are two critical indicators that doctors look for when trying to diagnose Alzheimer’s. “Roughly 20 percent of people have the plaques, but no signs of dementia,” said UCR Chemistry Professor Ryan Julian in a release. “This makes it seem as though the plaques themselves are not the cause.” Researchers focused on the different structures a single molecule can manufacture, known as an isomer. “An isomer is the same molecule with a different three-dimensional orientation than the original. A common example would …