Alzheimers is the most common cause of dementia and yet there are no cures for it. Some drugs help ease the symptoms associated with Alzheimers, but there have not been any clinical studies with positive outcomes. A new study found that flashing lights and sounds at 40 Hz might be what patients need to reverse signs of Alzheimer's.
A study was conducted on a group of mice who were genetically altered to develop Alzheimer's symptoms and pathology. One group developed neurofibrillary tangles inside their neurons. Neurofibrillary tangles can lead to the cell's death due to knots of a protein called tau. Another group of mice developed amyloid-beta plaques. These plaques are toxic to nerve cells and work by damming the flow of communication between neurons. All the mice in the study had irregular brain activity in the "gamma range of brain waves that oscillate between 30 to 100 times a second."
Neuroscientist Li-Huei at MIT was working on an experiment to manipulate the brain activity of mice by flashing lights 40 times a second. This caused the brain of the mice to flicker generating gamma waves. She then realized that the amyloid plaques and tau protein levels had dropped. The flickering lights triggered a rush of microglia, which keep the brain clean from toxic waste and debris. They are the immune cells for the brain. This process was primarily focused on the visual cortex of the brain. To penetrate deeper into the brain she added noise at a frequency of 40-Hz. The study showed that after seven days of listening to noise and looking at flickering lights for one hour, the levels not only decreased in the visual cortex, but also in the hippocampus and prefrontal cortex of the brain.
To test this experiment the group of mice were given a familiar and unfamiliar object to detect. The mice who were not given the treatment did not recognize the familiar object, but the mice who were given the treatment spent 67% less time examining the familiar object. Jorge Palop, a neuroscientist, mentioned how the light and sound can be acting as a metronome for the mice, correcting the brain's abnormal activity daily.
Tsai says, “This is the first time we’ve seen that this noninvasive stimulation can improve cognitive function. It’s not a drug or an antibody or anything, it’s just light and sound.” Human studies are underway and to see any conclusive result will take >5 years time.