A recent study by MIT found a low-pitched buzz-like sound and strobe lights can be used to replicate brain waves impeded by Alzheimer’s, which improved cognitive function and helped remove plaque in mice displaying symptoms of the disease. The approach hasn’t been tested in humans yet, but if it’s possible to copy these results, it might turn into a drug-free, inexpensive way to treat this condition.
The Secret: Applying Sound and Light at the Same Frequency
The study in question follows up on a previous one, which showed that flashing light and playing sound 40 times a second into the eyes of mice with Alzheimer’s, improved their condition.
According to MIT researcher Li-Huei Tsai, there is substantial reduction of amyloid protein and increased prefrontal cortex engagement when visual and auditory stimulation is combined over a period of one week. The prefrontal cortex is the part of the brain most active in cognitive functions.
The researcher adds it is necessary to find a way to check if this treatment will work for humans. One issue with the effect is that it is limited to visual parts of the brain, bypassing important zones that play key roles in memory formation and retrieval.
Oscillations May Facilitate Recovery
Admittedly, the practical applications of the method seem rather limited. Yet, results indicate a possible approach for oscillations to facilitate recovery from Alzheimer’s. Our neurons, the brain’s nerve cells, generate electromagnetic waves. These brain waves help keep remote regions in sync.
One of these waves, running at gamma frequency, passes through the brain at an average of 60 waves per second. This wave is most pronounced when we’re trying to remember something and trying to focus. People suffering from Alzheimer’s have an impedance of these gamma waves.
This study into the role of sound in facilitating recovery from Alzheimer’s isn’t the first of its kind. Previous studies have explored the role sound can play to clear amyloid and tau proteins in the brain, which are partially responsible for the condition.
More specifically, it has been shown that bursts of ultrasound encourage the microglia, the “waste-removal” part of the nervous system to be more active and also made blood vessels leakier in order for treatments to penetrate the blood-brain barrier and take effect.
Impediment of Gamma Waves Associated with Alzheimer’s
One previous study has suggested the impediment could play a pivotal role in development of the condition. One way to “trick” the brain to produce more gamma waves is by using light. In other areas, this can be managed by sound.
The sound researchers used was barely audible at just 40 Hertz, but exposing mice to only an hour of this monotonous droning sound every day for seven days resulted in notable stimulation of blood vessels and microglia and a significant drop in the amount of amyloid protein accumulation in the auditory areas.
According to Tsai, the team of researchers effectively demonstrated that it was possible to apply a completely different sensory modality to provoke gamma frequencies in the brain. The intervention also helped stimulate the hippocampus, which is believed to modulate short-term memory.
The effects go beyond brain chemistry. It emerged that the mice that underwent the treatment demonstrated better results on a variety of cognitive tasks. The effect was even more dramatic when light therapy was added from the previous study, clearing plaques in the prefrontal cortex among other brain areas. The microglia accumulated around the plaques on top of one another.
Future Development Potential
Preliminary safety tests have not shown any side effects of the process. Finding new mechanisms of how nervous systems sync activity and clear protein “debris” is a huge step in the direction of developing treatments for various neurological conditions, including Alzheimer’s.
It will undoubtedly take more work to translate discoveries like this to the brains of humans, particularly considering the differences between how gamma waves appear in the human and the mice brain, but the findings have amazing implications for future development.