Flickering screen: can Alzheimer’s disease be cured by sitting in front of the TV?

Every morning, Li-Hui Tsai meditates in front of a flickering screen. Synchronously with flashes of light, sharp sounds are heard, somewhat reminiscent of the clicks of a castanet of a flamenco dancer, only much louder. However, the rhythm here is not for entertainment.

The combination of flickering light and clicking sounds helps to synchronize the electrical processes in the brain, known as gamma waves.

For the uninitiated, such a light and sound procedure may seem like a new fad to wellness fans. But Tsai is a neurophysiologist from the Massachusetts Institute of Technology (Cambridge, USA). And she has evidence that this procedure can prevent the development of Alzheimer’s disease.

Li-Hui Tsai Research is a radically new approach to preventing and treating the most common form of senile dementia.

Today, about 50 million people worldwide suffer from dementia – and by 2050 this figure is expected to triple.

From the point of view of neurology (according to the prevailing hypothesis. – Ed.), The main change associated with Alzheimer’s is the accumulation of toxic protein (amyloid plaques) in the brain and the formation of clusters of tau protein inside neurons.

As a result, both processes seem to wreak havoc on our neurons and their synapses (places of contact between two neurons that allow them to “talk”).

Thus, it is not surprising that over the past three decades, most of the research on Alzheimer’s has focused on finding drugs to remove these plaques – and yet we are still waiting for a breakthrough.

And a series of new studies suggests that the answer may not be chemical, but electrical.

And it all depends on those gamma rhythms that seem to trigger a kind of cleansing operation in the brain, removing toxins before they begin to cause harm.

Healing brain waves

In everyday life, we often use the word “dawned” when it comes to a sudden surge of inspiration. In neurophysiology, what dawns on us are special waves in the brain, the rhythmic structure of electrical activity created by groups of neurons throughout the brain at a certain frequency.

In the same way that radio or television stations broadcast their signal on a specific wave, the various frequencies of the brain waves appear to be related to well-defined neurological functions.

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Gamma waves oscillate from about 30 to 100 times per second, they can usually be observed when we concentrate on something or try to remember something.

In some very interesting studies of the early 2000s, it was demonstrated that patients with Alzheimer are especially weak, in particular, gamma waves, the fastest brain rhythms (compared with healthy people without signs of mental decline), which suggests: violation of these rhythms may be involved in the disease.

However, it was not clear: either this is just another consequence of the onset of general neurodegeneration, or, potentially, its cause. And a team of scientists led by Tsai decided to figure it out.

To prove their hypothesis in principle, they first resorted to a technique known as optogenetics, when laboratory mouse neurons are genetically altered so that they respond to light of a certain color.

By placing a tiny light source in the animal’s skull, scientists can stimulate gamma waves with very high accuracy and observe the consequences of this.

Brain guard

And what they saw was amazing. Not only a significant reduction in amyloid plaques was observed. Researchers discovered the mechanism for their creation.

Of particular interest was the effect on the microglia of the brain (macrophage cells, a kind of emergency rescue team, bodyguards of our brain, taking care of its health).

“They are like immune surveillance,” Tsai explains. “They monitor the situation and can clean up pathogens, toxic waste, and foreign matter.”

In previous studies, it was found that in patients with Alzheimer’s, microglia often cannot properly perform their duties. But it seems that gamma waves can wake up macrophage cells, which leads to a decrease in the number of amyloid plaques and accumulations of tau proteins.

Moreover, the effect of applying gamma waves occurs very quickly. Just one hour of stimulation was enough to activate microglia and achieve a noticeable reduction in the number of amyloid plaques.

Such an effect of gamma waves on macrophage cells means a huge leap forward in our understanding of Alzheimer’s disease (and the function of gamma waves), Tsai emphasizes.

Optogenetic stimulation, however, is a procedure that is not so easy to apply in humans. Therefore, in the next step, Tsai tried to check whether less invasive forms of brain wave synchronization would work.

In one experiment, scientists every day for an hour illuminated mice with light flickering at a frequency of 40 Hz, and in other experiments, animals heard quick clicking sounds at this frequency.

And in each case it worked, synchronization ensued. Macrophage cells worked more actively, the level of toxic proteins decreased.

It is also important that all this affected the behavior of mice. Those who received stimulation quickly found a way out of the maze and remembered it better – unlike those who were aging without stimulation.

Beneficial vibrations

But will scientists be able to repeat these results in real patients with Alzheimer’s?

Tsai is now embarking on clinical trials to investigate the long-term benefits of stimulating gamma waves for humans.

But in another study, some inspirational evidence has already been obtained confirming that such stimulation does lead to an improvement in cognitive abilities.

The study, led by Amy Clements-Cortes of the University of Toronto (Canada), conducted not only auditory, but also tactile stimulation. Participants diagnosed with different stages of Alzheimer’s disease sat in a chair with six speakers that made low sounds at the frequency of gamma waves.

This was reminiscent of the action of a subwoofer (low frequency speaker system), Clements Cortes says, which caused participants to feel light vibrations all over their bodies.

After six 30-minute procedures, patients showed improvements in standard tests for various cognitive abilities, including in the mind and in short-term memory.

This seemed especially surprising when you consider how short the gap was during the stimulation, Clements-Cortes notes.

She also has evidence from another patient with mild signs of dementia, who used a similar device at home for three years. “Three years later, we came to visit her,” says Clements-Cortes. “Her mental abilities did not deteriorate, they remained about the same.”

Clearly, much more data needs to be collected, with larger samples, but the initial results, according to Clements-Cortes, are “incredibly inspiring.”

It is possible that patients will be able to receive this kind of therapy simply by watching TV or listening to the radio, she says.

Is it after so many years of fruitless attempts to find Alzheimer’s treatment at the end of the tunnel that the light has finally dawned?

It seems that the new method may be especially valuable for early intervention during the course of the disease.

Martin O’Halloran of the Irish National University points out that although patients may have cognitive difficulties, it takes a long time to confirm the Alzheimer diagnosis and this delays the start of treatment because doctors don’t want to risk side effects until they are confident in the diagnosis .

“Any early intervention for such patients should be as non-invasive and safe as possible,” he says. “Including using flickering light or a repeating sound.” (This is not suitable for patients with epilepsy, since stimulation can provoke a seizure.)

Barry McDermott, a researcher at Irish National University, is also optimistic about the results.

“No doctor will prescribe Alzheimer’s medicine for prevention, but this method is something that you can start using in advance,” he notes. “It’s so simple and easy. Theoretically, you can even have such an application on your smartphone.”

Despite rapid advances in research, both O’Halloran and McDermott, who recently wrote a technology potential review for the Alzheimer’s Journal of Research, emphasize that many questions remain to be answered.

Besides the need to obtain more serious evidence of the long-term usefulness of the method during clinical trials, one must also understand what frequency of gamma waves is ideal for use and what is the optimal duration of use.

Although it seems unlikely that you will receive an overdose of gamma waves, it will be useful to find out if excessive enthusiasm for using the method will cause side effects, Irish scientists emphasize.

In addition, it remains to be seen whether stimulation of gamma waves improves the mental abilities of healthy people.

Tsai is careful here: she believes that there is a certain limit to what gamma waves can do for a healthy brain.

But she hopes that the method can be useful as a preventative measure after a person has overcome middle age – in order to maintain the normal functioning of the brain before the first signs of mental decay appear. “I think it’s possible,” she says.

Despite many questions that have yet to be answered, Tsai is already testing the device on himself. “And I feel great,” she says, smiling slyly.

Like any scientist, Li-Hui Tsai understands that her personal experience cannot be accepted as convincing evidence. However, if the results of her research are confirmed, many of us, quite possibly, will start our day with similar sound and light procedures – in order to keep our brain healthy.

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David Robson lives in London and writes on non-fiction topics. Recently released his book, The Trap of Intelligence. Why Smart People Do Nonsense.

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Read the original article at BBC Future website

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