WASHINGTON, March 14 (Xinhua) -- American neuroscientists found that light and sound stimulation can improve cognitive and memory impairments in mice, signalling a possibility to treat Alzheimer's disease.

The study, published on Thursday in the journal Cell, showed that a combination of visual and auditory stimulation to induce brain waves known as gamma oscillations could clear amyloid plaques in mice brains, including areas critical for learning and memory.

Previous studies showed that Alzheimer's patients have impairments of their gamma-frequency oscillations. The oscillations range from 25 to 80 hertz and are believed to contribute to brain functions such as attention, perception, and memory.

The researchers at Massachusetts Institute of Technology and Georgia Institute of Technology found that flickering light at 40 hertz combined with auditory stimulation can reduce plaques in the prefrontal cortex where higher cognitive function take place.

The treatment also stimulated the activity of debris-clearing immune cells known as microglia, which pile on top of one another around the plaques.

In an ongoing study, the researchers are analyzing how gamma oscillations affect specific brain cell types and they have performed some preliminary safety tests of this type of stimulation in healthy human subjects.