Alzheimer's 'breakthrough:' noninvasive ultrasound technique restores memory in mice

In the USA, a person develops Alzheimer's disease every 67 seconds. By 2050, it is estimated that as many as 16 million Americans will have the disease. But researchers from the Queensland Brain Institute at the University of Queensland in Australia say they have made a "breakthrough" in treatment for the condition: a noninvasive ultrasound technology that can restore memory.

When used on the brains of Alzheimer's mouse models, the team found the ultrasound technique successfully cleared beta-amyloid plaques in 75% of mice.

The word 'breakthrough' is often misused, but in this case I think this really does fundamentally change our understanding of how to treat this disease, and I foresee a great future for this approach.

In their study, recently published in the journal Science Translational Medicine, researchers at the Clem Jones Centre for Ageing Dementia Research - reveal how the new ultrasound approach removed beta-amyloid plaques from the brains of Alzheimer's mouse models, restoring their memory.

Beta-amyloid is a protein fragment, or peptide, believed to be involved in the development of Alzheimer's. As we age, fragments of beta-amyloid can clump together in the brain, forming plaques that accumulate in the spaces between nerve cells, called synapses.

Though it is unclear exactly how beta-amyloid plaques contribute to Alzheimer's disease, studies have suggested they interfere with communication between nerve cells, making it difficult for them to survive. This can lead to cognitive decline and memory loss.

A number of studies have investigated the use of drugs to combat beta-amyloid build-up in the brain. In May 2014, for example, a different team of researchers reported on a study revealing how a commonly prescribed antidepressant reduced beta-amyloid production in Alzheimer's mouse models.

But no drugs are involved in the approach described by this latest research, potentially offering a less expensive and noninvasive treatment option for patients with Alzheimer's.

Ultrasound method 'restored memory to levels seen in healthy mice'

The research team's technique involves directing repeated scanning ultrasound (SUS) to the brain in order to temporarily open the blood-brain barrier.

When used on the brains of Alzheimer's mouse models, the team found the SUS technique successfully cleared beta-amyloid plaques in 75% of mice.

The ultrasound waves oscillate tremendously quickly, activating microglial cells that digest and remove the amyloid plaques that destroy brain synapses.

In three memory tasks, the team found the mice treated with SUS performed significantly better than mice that were not treated with the ultrasound technique. In fact, the researchers say their memory was restored to levels seen in healthy mice.

These latest findings suggest that repeated SUS is useful for removing [beta-amyloid] in the mouse brain without causing overt damage, and should be explored further as a noninvasive method with therapeutic potential in Alzheimer's disease.

The researchers want to see whether the SUS technique could also be useful for restoring executive functions - such as decision-making and motor control. In addition, they plan to investigate whether the method can be used to clear toxic protein fragments involved in other neurodegenerative diseases.

Earlier this month, we learned from a study published in the journal Brain, in which researchers identified beta-amyloid accumulation in the brains of adults as young as 20 years old.

References:

1.  Scanning ultrasound removes amyloid-β and restores memory in an Alzheimer’s disease mouse model, Jürgen Götz, Gerhard Leinenga, Sci Transl Med, doi: 10.1126/scitranslmed.aaa2512, published online 11 March 2015, abstract.
2.  The University of Queensland news release, accessed 12 March 2015.
3.  Additional source: Alzheimer's Association, Alzheimer's facts and figures, accessed 12 March 2015.