Alzheimer's disease is currently marching through the brains of some 5 million Americans, eradicating vast swaths of memories in a seemingly irrecoverable assault on cognition. But what if those memories were recoverable, that devastating assault reversible? Scientists in the journal Science Translational Medicine think they have a solid shot at just that based on a new ultrasound-based therapy they've tested on mice. By directing noninvasive ultrasound waves to the brains of mice, they were able to activate a type of cell called microglia, which essentially attacks things that don't belong in the brain, reports Popular Science. These cells dramatically cut a plaque—amyloid-β peptide, which can disrupt brain cell communication—whose buildup has long been associated with Alzheimer's by as much as 75%.
For years it's been tough to penetrate the blood-brain barrier, which separates and protects the blood and chemicals within the brain from those beyond, to get to these protein tangles. But scientists found that by using ultrasound alongside a microbubble injection they were able to temporarily open a pathway through the barrier without causing any brain damage or impairment. They then observed that over the course of weeks of followup, the mice who received the ultrasound treatment continued to perform better on both memory and spatial recognition tests. But hold the victory dances: Though it shows big promise, "there is a long way to go before this noninvasive technique could be translated into a practical treatment for Alzheimer's," one researcher not affiliated with the study tells the LA Times. Next up: Test sheep before moving to human trials. (Check out which drugs are associated with an increased risk of developing Alzheimer's.)