Flashing lights could form basis for new Alzheimer’s treatments

A combination of flashing and clicking lights could be a radical new approach to preventing and treating Alzheimer’s disease, reports the BBC. It has focused on the work of Li-Huei Tsai, a neuroscientist at the Massachusetts Institute of Technology in Cambridge, USA, who has evidence that this type of therapy could be effective.

Ms Tsai’s research sees an individual clicking a light in rhythm with a flashing screen in order to train the brain. It synchronises the electrical activity known as gamma waves, which have been found to trigger the removal of toxins in the organ before they can cause any damage to memory and cognitive function.

Previous research into Alzheimer’s has identified that amyloid plaques build up outside of cells and tangles of tau proteins establish themselves within neurons. As a result, neurons and the synapses that connect them are damaged, leaving irreversible neurological changes in the patient. This has led to much of the drug development work of the past 30 years focusing on the removal of these plaques, but there’s yet to be a breakthrough.

In a change of direction, new studies are starting to look into the idea that electrical, as opposed to chemical, treatments may be required. In neuroscience, the term brainwave refers to the rhythmic way electricity is produced by neurons firing together at the same frequency in the brain. Each frequency seems to be associated with a specific neurological function, opening up an interesting line of investigation for Alzheimer’s treatment research.

Gamma waves, which have a frequency of between 30 and 100 oscillations a second, are used for encoding and retrieving memories. A number of studies conducted around 20 years ago reported weak gamma waves being observed in Alzheimer’s patients, prompting scientists to believe that a disruption to this rhythm in the brain could be connected to the disease.

What hasn’t been clear is whether this disruption is a symptom or a cause, leading Ms Tsai’s team to look into it in more detail. They stimulated gamma waves using a light source and found it had a profound effect on the brain’s microglia.

Ms Tsai explained what these special cells do: “They are like an immune surveillance. They survey the environment and they can clear away pathogens, toxic waste and foreign substances, and get rid of them.”

While research in the past has found microglia in Alzheimer’s patients not carrying out these important tasks, the gamma rays appeared to reawaken them. This led to fewer amyloid plaques and tau protein tangles in the brain, providing hope for Alzheimer’s sufferers. Notably, the effects were quick, with just an hour of gamma waves showing a significant reduction of amyloid plaques.

Ms Tsai summarised: “When we saw the changes in microglia – that's when I realised that there is something very interesting going on.”

At present, there are around 850,000 people in the UK with dementia and 50 to 75 per cent of those have Alzheimer’s. As there is currently no cure, treatments rely on early diagnosis to be effective. The warning signs to look out for include memory loss, difficulty completing everyday tasks and changes in mood.