Scanning for Lagging Brainwaves Could Predict Alzheimer's Decades Before Memory Loss Starts

A study published in Cell Reports suggests a brain scan could predict Alzheimer's disease decades before symptom onset by detecting a sharp-wave ripple (SWR), a brain wave that plays a direct role in spatial learning and memory formation in humans, mice, and other mammals, reports the Daily Mail . SWRs also shield against Alzheimer's, and experiments with mice revealed those with SWR deficits performed worse on memory tasks 10 months later — or 30 years later in humans. "A major advantage of this approach is that researchers have recently developed a noninvasive technique for measuring SWRs in people, without implanting electrodes in the brain," said the University of California, San Francisco's Yadong Huang. The procedure could potentially improve clinical trials of new drugs to ward off Alzheimer's, by enrolling individuals already exhibiting SWR deficits. SWRs occur when the brain of a resting mouse or human rapidly and repeatedly replays a recent memory of moving through a space, with their abundance and short gamma (SG) power especially quantifiable. The researchers speculated that SWR measurements could predict the severity of demonstrable memory problems in mice carrying the apolipoprotein E4 gene, which elevates the risk of Alzheimer's in people, as they age. Results showed SWR abundance and SG power deficits at an early age predicted which mice's memory task performance would worsen when they were much older.