Nearly 36 million people worldwide suffer from Alzheimer's disease or a related dementia but a study conducted by two scientists could bring hope to these individuals.

The researchers found that non-invasive ultrasound technology can be used for treating Alzheimer's disease and restoring memory at least in experiments with mice.

For their new study published in the journal Science Translational Medicine on March 11, Gerhard Leinenga and Jürgen Götz, from the University of Queensland in Australia, successfully restored the memory function of mice that were bred to develop Alzheimer's disease using sonic waves, which were initially used by submarines in World War II.

The researchers deposited amyloid-β, the main component of amyloid plaques that are present in individuals suffering from Alzheimer's disease, into the brains of the mice to come up with a mouse model of the neurological disorder.

The mice were then subjected to repeated ultrasounds. The ultrasound waves oscillate very fast activating the microglial cells that digest and remove the amyloid-β plaque.

The researchers found that the mice that received the ultrasound treatment performed far better on tests that evaluate long-term memory, spatial memory and short-term memory compared with the mice that were not subjected to the ultrasound.

It also appeared that the treatment can restore lost memories. In a maze that tests the ability of the mice to navigate, the mice that received the ultrasound treatment and whose cognitive function had already degraded because of the amyloid plaques accumulating in their brains were found to have reverted to their normal level of navigational skills.

When the researchers examined the brains of the treated mice, they also found that the activated microglial cells consumed a lot of the amyloid-β.

After six to seven weeks of receiving treatment, the amyloid plaques in the treated mice were reduced by 56 percent. The average density of amyloid plaques in their brains was also found to have nearly halved.

The researchers acknowledged that the human brain is different from the brain of the mouse but the researchers believe that the ultrasound approach could be more effective compared with Alzheimer's drugs when applied early.

"Treated AD mice also displayed improved performance on three memory tasks: the Y-maze, the novel object recognition test, and the active place avoidance task," the researchers wrote. "Our findings suggest that repeated SUS is useful for removing Aβ in the mouse brain without causing overt damage, and should be explored further as a noninvasive method with therapeutic potential in AD."

Photo: Cristian Iohan Ştefănescu | Flickr