A possible new use has been discovered for an old epilepsy drug -- giving people with Down Syndrome new capacity for learning. An article in Nature Neuroscience suggests that the drug, pentylenetetrazole, or PTZ, helped specially-bred mice with Down Syndrome to learn more like normal mice. Apparently PTZ, which is no longer approved for use with humans, stimulates brain cells and enhances learning. "This treatment has remarkable potential," said Craig Garner, a professor of psychiatry and a director of the Down Syndrome Research Center at California's Stanford University. "So many other drugs have been tried that had no effect at all. "Our findings clearly open a new avenue for considering how cognitive dysfunction in individuals with Down syndrome might be treated."