An Hour of Light and Sound a Day Might Keep Alzheimer's at Bay

A study published in Cell suggests Alzheimer's symptoms could be reversed via a treatment that combines daily doses of light and sound, reports Scientific American . The research involved mice genetically altered to exhibit key symptoms and pathology of Alzheimer's, with one batch of mice forming neurofibrillary tau tangles within brain cells, while another batch developed amyloid beta plaques. Both batches also had irregular brain activity in the gamma range of brain waves that oscillate between 30 and 100 times a second. Flickering a light at the mice 40 times a second, or 40 hertz, caused their brains to flicker back, producing gamma waves at a corresponding 40 hertz. Postmortem analysis showed the volume of amyloid plaques and tau tangles in the mice exposed the light also shrank. Further tests in which mice were exposed to both the flashing light and a droning sound for an hour a day for seven consecutive days showed amyloid plaques and tau tangles began falling in not only the audio and visual cortices, but the prefrontal cortex and the hippocampus as well. "These are the learning and memory centers of the brain," says the Wake Forest School of Medicine's Shannon Macauley. "And there was about a 40 or 50 percent decrease in amyloid and tau levels."