Applied to the whole brain, the ultrasound improved both the formation of blood vessels and the regeneration of nerve cells.

Led by cardiologist Hiroaki Shimokawa, a team at Japan's Tohoku University started with two groups of mice. One group underwent a surgical procedure that reduced blood flow to the brain, simulating the effects of vascular dementia, while the other group was genetically engineered to have an Alzheimer's-like condition.

Next, the scientists applied low-intensity pulsed ultrasound (LIPUS) to the brains of animals from both groups, in three 20-minute sessions per day. The vascular dementia mice received these thrice-daily treatments every other day for five days (for a total of three treatment days), and the Alzheimer's mice were subjected to 11 treatment days spaced over a period of three months.