Could people’s eyes and ears help fix the damage Alzheimer’s disease does to the brain? Just by looking at flashing light and listening to flickering sound?
A new study led by a prominent MIT neuroscientist offers tantalizing promise. It found that when mice engineered to exhibit Alzheimer’s-like qualities were exposed to strobe lights and clicking sounds, important brain functions improved and toxic levels of Alzheimer’s-related proteins diminished.
What’s more, the rapid-fire soundtrack appeared to make mice better at cognitive and memory skills, like navigating mazes and recognizing objects.
Of course, mice are not people. And many drugs that have helped Alzheimer’s-engineered mice haven’t done much for people with Alzheimer’s, which affects 44 million people worldwide, including 5.5 million Americans. Also, because the technique didn’t have long-lasting effects — results faded about a week after the sensory stimulation was stopped — any therapy developed from the research might have to be repeated regularly.
Still, seeing that a noninvasive daily dose of light and sound could have such significant effects in mice give some experts reason for optimism.
The experiments were led by Li-Huei Tsai, director of MIT’s Picower Institute for Learning and Memory. She and her colleagues showed that light and sound delivered to mice at a certain frequency — 40 hertz or 40 flashes or clicks per second — appears to synchronize the rhythm of the brain’s gamma waves, which is disrupted in patients with Alzheimer’s.
Somehow — neither Tsai nor outside experts are quite sure how — 40 hertz produces a gamma-wave oscillation that appears to increase activation of cells called microglia, which perform trash-clearing and immune-regulating functions. The microglia became more efficient at chewing up the amyloid protein that forms toxic plaques in Alzheimer’s.
“The effects on cognitive function are pretty big,” said Dr. Walter Koroshetz, director of the National Institute of Neurological Disorders and Stroke, which funds some of Tsai’s work. He said the results of the study, published Thursday in the journal Cell, are “definitely something that I don’t think anybody could have predicted.”
Experts cautioned that people should wait for clinical trial results and shouldn’t suddenly start illuminating their homes with disco strobes or pipe clicking sounds through their earbuds.
Still, said Koroshetz, sensory treatment is likely to be safe for most people.
“The study is very preliminary; it was conducted over a very short period of time and in mice, and mice are not people. At the same time, the research was done by a top research group and published in a leading research journal. With those caveats, the Alzheimer’s Association believes this area of research has a lot of potential,” said Keith Fargo, director of scientific programs and outreach at the association.
“The Alzheimer’s Association is encouraged to see dementia researchers taking new and different approaches, and - as the leading nonprofit funder of Alzheimer’s research - we also will continue to fund this type of research,” Fargo said in an e-mail.
“People should not try this approach at home,” he said. “Until this idea and the related techniques are rigorously tested in people in randomized controlled clinical trials, we won’t know the approach is safe.”
Researchers released an audio file that was a close approximation of the sound played for the mice. It vaguely resembled an electric motor of some kind, a little bit as if the compressor in a refrigerator had broken.
Martin Finucane of the Globe staff contributed to this report.