In the last two years, researchers have had some success in fighting off the suspected cause of Alzheimer’s in mice without using drugs. The first proposed technology used light pulses to alter brainwaves and now researchers believe it can also be achieved (and with more success) with sound waves.
Researchers from the Massachusetts Institute of Technology have exposed a group of mice to a hum at 40 Hertz (similar to the lowest E on a piano) and discovered that they develop half as many amyloid beta plaques in their auditory cortices and hippocampus compared to a control group. The research was presented at the Society for Neuroscience conference in Washington DC in November and is reported by New Scientist.
By using such a sound for just an hour a day, researchers were able to induce high-speed brainwaves that were able to break down the proteins. These waves, known as gamma waves, are the waves fired by our brain when we are doing particular mental activities such as perception, attention, and memory.
Gamma waves can range from 25 to 100 Hertz, with the typical one being around 40 Hertz. In previous experiments from the same team, the gamma waves were not induced with sounds but with light. In a paper published in Nature, they describe exposing mice to flickering light at 40 Hertz.
Over the last year, the team realized that audio stimulation is not as limited as visual stimulation and is more effective in reaching the hippocampus, where memories are stored. Once the brain is flushed with gamma waves, two effects come into play: fewer amyloid plaques are produced and more of these existing plaques are cleared out by immune cells known as microglia.
The cause of Alzheimer’s is still not known for certain, but the general consensus points the finger at the accumulation of certain proteins, such as amyloid beta. The mice in the experiment were used as animal models and genetically engineered to develop an ailment similar to Alzheimer’s.
The gamma way approach is already being trialled in humans, both in medical settings and privately (since as a therapy, listening to a hum for an hour seems quite safe). It will take time to know if this approach works. The mice used had no symptoms or were in the early stages of the disease. And while extremely useful, the mouse model might not translate to humans.
Over 30 million people suffer from Alzheimer’s disease worldwide and it is the most common cause of dementia.
[H/T: New Scientist]