MIT neuroscientists are testing a headset that uses a 'disco' of light and sound to treat Alzheimer's disease

• Alzheimer's disease is a complicated and debilitating disease that has no cure.
• One startup is testing whether a "disco" of light and sound can slow the disease in patients.

For decades, biotech companies have struggled to develop treatments for Alzheimer's disease, a disorder that causes loss of memory and other mental functions and affects roughly 6.5 million Americans.

Now they're slowly making progress. A drug was approved this year that can slow the disease's progression, sparking renewed optimism for the field. Companies are targeting new types of treatments, too.

Cognito Therapeutics is among them. The startup is testing whether a "disco" of light and sound, delivered via a special headset, can slow the disease in patients by stimulating their brains. The company just raised $73 million from investors to evaluate its technology in about 500 people with early- to midstage Alzheimer's disease.

"There is an urgent need to develop novel therapies that can safely delay the onset and progression of these neurodegenerative conditions," Brent Vaughan, Cognito's CEO, said in a statement.

Earlier Cognito studies found the technology could slow the atrophy of white matter in people's brain, a sign it could help fight Alzheimer's. Still, more study is needed.

Cognito's headset is based on research by the MIT neuroscientist Li-Huei Tsai, who cofounded the company with the MIT neurotechnology professor Ed Boyden. At MIT, Tsai and her team found that mice exposed to light delivered at a specific frequency had improved memory and lower amounts of amyloid in their brains, findings that suggested the device could help with Alzheimer's.

In a TED Talk, Tsai said the mice experienced a "disco" that affected important parts of their brains.

"The effect reaches key parts of the brain, such as the prefrontal cortex, where we do planning and reasoning, and the hippocampus, where we create memories," she said.

Cognito's current trial is expected to be completed by the end of next year, and data will be released in the first half of 2025, Vaughan said. If the trial shows the technology works, Cognito could use the results to ask regulators to approve the device.

In the trial, patients will be split into two groups. Half will wear Cognito's headset for an hour every day at home for a year. The others will don a "sham sensory-stimulation system."

Researchers will evaluate whether Cognito's headset can slow the progression of Alzheimer's disease based on results from commonly used tests that assess cognitive impairment and the ability to perform everyday tasks.

The device, which looks like a blend of sunglasses and headphones, emits pulsing lights and sounds. The light and sound target immune cells, called microglia, in the brain, and stimulate gamma waves, or repetitive brain patterns that are associated with cognitive function. Disrupted gamma waves have been seen in patients with Alzheimer's. Microglia help clear out amyloid, or proteins in the brain that are thought to be a major indicator of Alzheimer's disease.

"We realized one can use noninvasive visual stimulation, first of all, to change how neurons behave in the brain and, secondly, to induce cellular and biochemical changes in the brain," Tsai told Insider. "And I think that is perhaps the most unexpected result."