Recent research by Dr. Li-Huei Tsai and her colleagues at Massachusetts Institute of Technology (MIT) has demonstrated the power of flickering light in combating Alzheimer’s disease in mice.
Alzheimer’s disease affects over 5 million people in the US alone. It is a type of dementia that effects learning, intellectual ability, memory and behavior. Dr. Alois Alzheimer discovered clumps of amyloid plaques and tangled tau brain fibers in a woman’s brain in 1906. Another notable feature of Alzheimer’s disease patients is lack of healthy gamma wave oscillations. So far, attempts to use drugs to prevent or clear amyloid plaque formation have been unsuccessful.
Brainwave Activity
Inside the human brain are billions of different neurons. The junctions between different neurons are called synapses. Electrical signals fire through the brain synapses, bringing millions of neurons into synchrony in cycles, or waves. These are known as brainwaves. The speed and amplitude of these brainwaves are linked to certain states of consciousness, which are classified into five distinct categories. These brainwave frequencies range from delta waves (.5-3hz) to gamma waves (25-100+hz). Your synapses actually fire in all of these different frequency waves simultaneously, however one frequency at a time is usually dominant. Each person’s brainwave signatures (combinations of waves including amplitude of each brainwave) are unique.
Gamma Brainwaves and Dr. Tsai’s Study
Gamma brainwaves, which are impaired in patients diagnosed with Alzheimer’s disease, are the highest frequency of brainwaves. They are associated with higher learning, deep meditation, altruism and communication between different parts of the brain.
Instead of trying to directly clear the amalyoid plaques or untangle the tau fibers, Dr. Tsai and her team focused on the gamma wave. They found that they could encourage the mice’s brain to produce gamma waves by using flashing lights at 40hz. Microglia (the brain’s cleanup crew) were activated by this stimulation and returned to the their normal job of assisting with the immune response by consuming the harmful amyloid beta plaque.
Therefore, after flashing a 40hz frequency for 1 hour at mice with Alzheimer’s disease, Dr. Tsai and her team found a 50% reduction of beta amayloid plaques. The original effects only worked for 12-24 hours. After this period the microglia became sluggish again and the amayloid plaques began to build back up. Thus, they tried again. This time they gave the mice 1 hour of 40hz stimulation for 7 days in a row. They saw great improvement. They also saw a marked decrease in the tangled tau fibers in the brain, which is another main feature of Alzheimer’s disease.
The Bottom Line
As Alzheimer’s is considered an irreversible and progressive brain disorder, this study represents very exciting research. Whether this will work on humans as effectively as mice remains to be seen. As Dr. Tsai herself commented as the main result of the study, “Our findings uncover a previously unappreciated function of gamma rhythms in recruiting both neuronal and glial responses to attenuate Alzheimer’s-disease-associated pathology.”
Also exciting though is Dr. Tsai’s approach, which activates the brain back to normal functioning without drugs, so that it can heal itself.
Access the full journal article here: http://www.nature.com/nature/journal/v540/n7632/full/nature20587.html
Listen to an entertaining podcast about it here:
http://www.radiolab.org/story/bringing-gamma-back/