In December 2016 a research article reported in the journal Nature that some success had been found in the removal of amyloid plaques associated with Alzheimer’s Disease in mice. The intervention used involved the use of gamma brain waves, i.e. brain waves at around 40Hz. This original work used light pulses at 40 Hz. Unsurprisingly the brain areas affected by the intervention were those involved in vision. Later work used audio stimulation, also tuned to 40Hz (approximately the lowest ‘E’ on a piano) as well as light, and also vibration. The rationale behind this was to affect as many areas of the brain as possible. Particular interest was focused on the audio intervention, as the brain areas involved in hearing are physically close to some of the areas in evolved in memory formation and storage, i.e. the hippocampus. Memory loss is, of course, one of the most well-known symptoms of Alzheimer’s Disease. To quote from the research abstract:
‘Our findings uncover a previously unappreciated function of gamma rhythms in recruiting both neuronal and glial responses to attenuate Alzheimer’s-disease-associated pathology.’
Nature (February 2018] gives a layperson’s description of the theory and results to date. The article also reported that, with successful results in mice and no requirement for the usual safety trials before the intervention is tried on human subjects – the intervention involves no medical, pharmacological or surgical processes – the original researchers are trialling the intervention in a care home in Boston, Massachusetts, USA.
New Scientist (2 February 2019) reported that a landmark study had concluded that bacteria involved in gum disease could be part of the cause of Alzheimer’s Disease in humans. This offers exciting new possibilities for research and even the development of preventative and therapeutic interventions. It also offers an intriguing potential link between the studies that led us to develop this app and this new work. Microglial cells, the non-neuronal cells in the brain that seem to have increased in the mouse studies using gamma wave stimuli, ‘act as the first and main form of active immune defense in the central nervous system’. So the stimulation of microglial activity might affect Alzheimer’s Disease via attacking the bacteria that seem to be part of the cause – and any effect on amyloid plaques is of secondary importance. We just don’t know; more research is needed and our app can play a small part in that.