Alzheimer’s disease is a complex disease with many moving parts. As of today, no one is exactly sure what causes it or what can be done to prevent it. There are theories, and some of those are based on findings of scientific research studies. Even with the brightest minds continually working on finding a successful treatment or cure, it seems a cure may not be found for a long time.
Though the results of a newly published study out of MIT did not find a cure, they unveiled an interesting insight into the brain. Led by Li-Huei Tsai, Director of the Picower Institute of Learning and Memory at MIT, the study found that introducing flashing LED light into the brains of mice suffering from Alzheimer’s disease reduced the percentage of Alzheimer’s disease causing beta amyloid plaques in the brain by about 50%. This study was done on mice, but if their findings do end up working on people, we could be quite a bit closer to treatment – or someday even a cure.
Tsai and her colleagues at MIT were working with mice who had signs and symptoms of Alzheimer’s disease. One of their experiments involved using electrical impulses in an attempt to recreate the neuron firing that occurs in healthy brains. (Neuron firing slows down in the brain when people have Alzheimer’s disease.) Our brains have billions of neurons (nerve cells in the brain), and they talk to each other, reaching out to each other and communicating with electrical signals. When groups of neurons are “on” together in the same “beat” so to speak, we are able to process information and understand the world around us. The “beats” per minute between neurons depend on the difficulty of the tasks we’re performing. The neurons fire more slowly when we’re sleeping, and when we’re performing difficult tasks that require thought (or new tasks), the neurons fire (or beat) more quickly, at between 30 and 100 times per minute. This rate is considered the gamma frequency.
One of the problems in people suffering from Alzheimer’s disease is that the neurons get fatigued and quieter, so cognitive tasks become more difficult for the brain to process. There are other problems in brains affected by Alzheimer’s disease too, like beta amyloid plaques, muddled connections between neurons, and problems with immune cells. But this study focused on the neuron firing.
What Tsai and her team did was attempt to speed up the neuron firing to the gamma frequency (30 to 100 per minute). They started with mice that had multiple problems, including lots of beta amyloid plaques in the brain and less gamma (or slower neuron firing). They drilled a hole in the skulls of the mice and inserted a tiny fiber optic cable into the brain to fire light at a rate that matches the gamma frequency – in this case, 40 per minute. After one hour of being treated with the flashing lights in the brains, the mice had about 50% less beta amyloid plaque buildup. That finding surprised even the scientists.
It seems like the light ignited the “janitors,” of the brain called the microglia, which “clean” the brain of plaque so it doesn’t build up. In Alzheimer’s disease, the microglia seem to stop working, which many believe is one of the causes of the symptoms of Alzheimer’s.
Excited by their findings, the researchers decided they needed to find a less invasive way to test whether the light was actually causing the decrease in plaque. So they decided to try putting the mice in a room with LED lights flashing at a gamma frequency. They were shocked when it had the same effect as putting a fiber optic cable in the brain did. All the mice studied had a 40 to 50% reduction in amyloid beta plaque after one hour of treatment in the light flashing room.
They followed that study with another study in which they treated the mice with the light one hour per day every day for seven days. And again, the results were the same – a 50% reduction of amyloid beta. The biggest problem they had was that the amyloid beta levels returned to their original levels about 24 hours after treatment. More studies will have to be done to find out whether daily light treatment could have positive effects on Alzheimer’s disease symptoms over a long period, whether humans will experience similar reductions in amyloid beta, and if so, whether those reductions will affect the symptoms of the disease once it’s been diagnosed.
There’s still no magic pill. There’s no cure. But there is some fantastic information to use as a springboard to future studies.
Check back next week to learn about a follow up study led by Susumu Tonegawa, Director of the RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory at MIT, that relates to “bringing back” memories thought to be gone using a technique called optogenetics.
Learn more about Alzheimer’s disease on our website.