Another amazing Radiolab aired May 5, 2021 (Staph and Gamma) that revisited and provide updates on two simple scientific discoveries that potentially hold huge ramifications for our modern times. This episode began by replaying an earlier show Robert Krulsich did with Molly Webster back in 2016. At the time, this was breaking news. This episodes includes updates as of 2020.
Brainwaves
Li-Huei Tsai is a professor and director of the Picower Institute for Learning and Memory at MIT. Li-Huei explained to Molly how most research on Alzheimer’s disease (a disease that affects every family) has focused on genes predisposing people to developing this disease later in life. But, Li-Huei took a different approach at looking at this disease. Her work centers on gamma frequencies, which are like a beat in your brain (a type of brainwave).
Entire groups of neurons will beat at the same time. Some beat at 1 beat per second. Others beat at 600 beats per second. A person who needs to super focus his or her attention requires groups of neurons to beat at 30 to 100 beats per second. These are gamma beats. We can measure them through EEG recordings.
They look like this.
Brainwaves and Alzheimer’s Research
Li-Huei explains how the human brain has billions and billions of neurons. To do what we do as humans, process information, have a thought, problem-solve, communicate with each other, and remember things, all these neurons need to communicate with each other. The neural cell has long tentacles that reach out towards other neurons like waving hands. When an electrical signal passes through them, it is like a zap that sends a signal (neural transmitter) across the gap to another neuron, which turns it on.
To walk, write a poem, or compose a song, whole groups of neurons must turn on and fire in synchrony. The gamma frequency (or synchrony) has been considered very important for the higher order cognitive function. However, Molly Webster explains that when you look at an Alzheimer’s brain, what you see is there’s actually less gamma happening. Or people say, like, the power of gamma is reduced.
Li-Huei says this is because not all the neurons can be recruited to oscillate at the gamma frequency and this is because of plaques that build up around neurons gunking them up. the more plaque, the harder it is to think…sort of like cobwebs in the brain.
Let’s Manipulate Gamma Oscillations
So, Webster and Li-Huei wondered: What would happen if they could just bring gamma back to the brain?
Working with mice that have an early stage of Alzheimer’s disease measured by elevated levels of beta amyloid peptides, they drilled a small hole into the skull of the mouse’s head, slide a very thin fiber-optic cable into the brain (specifically, a group of cells modified to be sensitive to light), and then using blue laser light, flicker it at 40 beasts per second: a gamma wave.
They did this for one hour, the looked at the mice’s brain to see if anything was different. Not expecting to find much, they were shocked. After one hour of pulsing light, there was nearly half as much of the nasty plaque gunk filling up their hippocampus (a 40 to50% reduction of beta amyloid in their brain).
Who knew blinking light would do that? But, somehow, the pulsing light triggered the brain’s cleanup crew (microglia) that gobble up the gunk.
In a normal brain, these janitor cells are constantly gobbling up the gunk, but in an Alzheimer’s brain, it is sort of like the janitors have gone on strike. After one hour of light, the microglia cells seem to get a lot bigger, meaning they’ve gobbled up beta amyloid mucking up the brain.
With less gunk, more neurons are available to oscillate together at the gamma wavelength needed to concentrate and do higher level cognitive work.
Wait, It’s Even Better
These findings were really exciting, but drilling holes and inserting fiber-optic cable into brains is pretty invasive. So, Li-Huei wondered if there was another way to get light into the brain. Perhaps through the eyes?
So, they created a flicker room for the mice by using duct taped strips of LED lights. They put the mice in the altered cages and let the LEDs flicker at 40 beats per second. They let the mice bathe in the flickering LED glow for 1 hour. And then took a look at the amyloid beta levels in the visual cortex and once again found a 50% reduction.
Over time, they found out that if the mice are not put into the flicker-light room at least once for an hour every 24 hours, the plaque comes back. So, they are trying to see how to keep the levels down longer, or ever for good.
The Update to This Research
Since Radiolab first reported this research, Li-Huei has tried sound at 40 hertz per second for one hour with her mice.
The same thing! A 40 to 50% reduction in plague in the brain.
They are just moving into human trails, but there is a whole movement out there not waiting to find out the results. Here are just some of the interesting efforts underway, but people, companies, and meditation tapes aren’t waiting.
And there are many other products available.
Several other videos describing this light therapy include the following.
How to build your own Alzheimer’s light treatment relay with Arduino/Espruino
While far from conclusive and so far untested on humans, the results of the studies detailed in the podcast are extremely promising. The gist is by flickering light at and around the gamma frequency for extended periods of time, brain plaque caused by Alzheimer’s is dramatically reduced in lab mice.
This got me thinking how one would go about building a flicker box for this purpose if you wanted to try it out for yourself. My first thought was to just build a simple website (seizure warning):
