The researchers injected the mice the compound right after their birth and found that single injection enabled the cerebellum of the rodents' brains to grow to a normal size.

"Most people with Down Syndrome have a cerebellum that's about 60 percent of the normal size," lead author Roger Reeves of the Johns Hopkins University School of Medicine argued.

"We treated the Down Syndrome-like mice with a compound we thought might normalise the cerebellum's growth, and it worked beautifully," he said.

"What we didn't expect were the effects on learning and memory, which are generally controlled by the hippocampus, not the cerebellum," he said.

The team tested the mice who had been given the dose with the mice who suffered with the syndrome, and normal mice in a variety of ways, and found that the treated mice did just as well as the normal ones on a test of locating a platform while swimming in a so-called water maze.

Further research, however, is needed to know why exactly the treatment works and if it can be altered for human use, the researchers wrote in the journal Science Translational Medicine.