Brain Wave Oscillations and Alzheimer's Disease

   We have learned about the various techniques researchers use in their studies of the brain and how crucial they are to the knowledge of the brain that we have today. A few examples of these techniques are optogenetics, EEG, and tACS. The EEG played an extremely important role in brain studies because it allowed scientists to record electrical activity of groups of neurons in the brain by measuring their voltage changes as they are activated. When these groups of neurons fire, they do so in an oscillating pattern creating distinct patterns of different types of brain waves. Based on the type of brain waves that are occurring, we can use an EEG to record and predict the brain function that is occurring along with a specific brain wave type. For example, delta waves have the lowest frequency and occur during a deep sleep. Other types of brain waves that can be present are theta, alpha, beta, and gamma waves.
    Researcher Li-Huei Tsai and her lab published an interesting study in the scientific journal Nature. These researchers put these various techniques together in order to explore brain waves and their roles in neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. In this study, they used an EEG to record the brain waves from oscillating groups of neurons in groups of mice created to produce a hallmark sign of Alzheimer's- amyloid-beta plaques. They decided to test this because research has shown that brain waves can become disrupted in these diseases. Beta waves are shown to be increased in the motor areas in individuals with Parkinson’s disease and gamma waves are decreased in those with Alzheimer’s. Tsai and her lab designed flickering lights tuned to a specific frequency in order to have an effect on the brain waves of the mice and clear that amyloid-beta plaque out of the brain. Their interesting finding showed that the Alzheimer’s disease model mice that were exposed to a light from a disco had lower levels of amyloid beta than mice that were kept in the dark. Therefore, from their results it seems like the strobe lights indeed had an effect on the brain waves of the mice and assisted in plaque clearance from some brain areas.
     Another researcher, Randolph Helfrich, is also using techniques like transcranial alternating current stimulation (tACS) to affect brain oscillations.
    The manipulation of brain waves is currently being researched in not only neurodegenerative diseases, but also disorders like insomnia and schizophrenia. Tsai and another researcher, Ed Boyden, did begin testing their research in humans with Alzheimer’s as well. Unfortunately, a lot of the results that come from mice models don’t show the same results in humans. So, there is still a great deal to be done in using these techniques in order to use them in neurodegenerative diseases and other disorders.

Image Source: https://www.sciencenews.org/article/brain-waves-may-focus-attention-and-keep-information-flowing


Article Source: Helen, Thompson. "How Flashing Lights and Pink Noise Might Banish Alzheimer's, Improve Memory, and More" Nature. 28 February 2018.
https://www.nature.com/articles/d41586-018-02391-6