Alzheimer’s is a serious brain disease that affects millions of people worldwide. There’s no cure for it at the moment. The search for alternative treatments has been fueled by this. Recent research indicates that sensory stimulation may be a promising and noninvasive therapy.
In the last decade, researchers at The Picower Institute for Learning and Memory (MIT) have explored whether 40Hz “gamma frequency” sensory stimulation can help to treat Alzheimer’s.
The approach was initially tested on mice. It has gained worldwide interest since then, and there is growing evidence that it could improve brain health for both humans and animals. This new review describes progress, and highlights key clinical and scientific questions regarding this noninvasive treatment.
Li-Huei Tsai is a Picower Professor of Neuroscience at MIT and director of MIT’s Aging Brain Initiative. She was also the senior author on this new review, along with Jung Park. As we have made our observations in this field, other researchers have also published results that are very similar.
Researchers have discovered 16 genes that are linked with Alzheimer’s.
The key to achieving gamma is to use stimulation that occurs at 40 hertz. “They all experience beneficial effects.”
Tsai’s research has demonstrated that since 2016, 40Hz stimulation via light, sound or vibrations reduces Alzheimer’s-related issues such as amyloid proteins and tau protein, can prevent neuronal damage and improve memory for mice.
This stimulation triggered beneficial responses among various brain cells including microglia and neurons. By activating the glymphatic brain system, for example, 40Hz stimulated mice to clear amyloid.
The human trials conducted by Cognito Therapeutics and MIT have shown promising results. Participants who were exposed to light and sounds at 40Hz experienced a slower rate of brain shrinkage, as well as some improvements in cognitive abilities. Cognito has now launched a phase III study called GENUS, which will test the therapy in greater detail. The goal is to develop a non-invasive, safe treatment for Alzheimer’s patients.
Tsai and his MIT co-workers Edward Boyden, Emery N. Brown and Emery N. Brown inspired worldwide research on noninvasive gamma sensor stimulation as a possible therapy for Alzheimer’s. Its benefits are now supported by numerous studies. Researchers in China, for example, confirmed in 2024 that the 40Hz stimulation increased glymphatic flow in mice.
In a 2022 Harvard Study, 40Hz stimulation using Transcranial Alternating current significantly decreased tau proteins among three of four participants. A 2023 Scottish study of over 100 participants found that audiovisual gamma (at 37.5%Hz) stimulation improved memory.
GENUS, or Gamma Entrainment Using Sensory Stimulation (GENUS), is still a mystery to many people despite the progress made in clinical trials and research.
Tsai’s team is studying the cellular responses and molecular mechanisms, focusing on neuropeptides as well as how microglia cells react to gamma stimuli and their effects on diseases.
Understanding these mechanisms, while a phase III national trial is in progress, could help improve the treatment and increase its potential. Tsai says that deeper insight could optimize treatment, revealing how it can benefit other neurological disorders, including Parkinson’s disease, strokes, epilepsy and cognitive challenges caused by chemotherapy and multiple sclerosis. Her lab also explores its potential benefits for Down Syndrome.
Journal Reference
- Jung M. Park, Li-Huei Tsai. Noninvasive sensory stimulation therapies to fight Alzheimer’s Disease. PLOS Biology. DOI: 10.1371/journal.pbio.3003046
