The scientists at Johns Hopkins and the National Institutes of Health treated the Down syndrome-like mice with the compound they thought might normalize the cerebellum's growth.
For the current experiments, Roger Reeves and his colleagues used mice that were genetically engineered to have extra copies of about half of the genes found on human chromosome 21.
The mice have many characteristics similar to those of people with Down syndrome, including relatively small cerebellums and difficulty learning and remembering how to navigate through a familiar space.
Based on previous experiments on how Down syndrome affects brain development, the researchers tried supercharging a biochemical chain of events known as the sonic hedgehog pathway that triggers growth and development. They used a compound- a sonic hedgehog pathway agonist- that could do just that.
The compound was injected into the Down syndrome-like mice just once, on the day of birth, while their cerebellums were still developing. The team tested the treated mice against untreated Down syndrome-like mice and normal mice in a variety of ways, and found that the treated mice did just as well as the normal ones on the water maze test.
The study is published in Science Translational Medicine.
--ANI (Posted on 05-09-2013)