A controversial research paper suggesting that people taking the street drug Ecstasy for just one night might later develop Parkinson's disease has been retracted, after a labelling error was discovered on bottles used in the study reports New Scientist. George Ricaurte and colleagues at Johns Hopkins University School of Medicine in Baltimore published their work in Science in September 2002, provoking widespread alarm in the media. The team found that three consecutive doses of ecstasy, or methylenedioxymethamphetamine (MDMA), given to squirrel monkeys and baboons caused profound damage to dopamine-producing neurons in their brains. These are the neurons lost in Parkinson's disease. The animals were injected with MDMA at three-hour intervals to mimic the way humans take the drug at all-night raves. Two of the 10 died within hours after developing hyperthermia. But the group has issued a retraction in Science saying they discovered that all but one of the animals received amphetamines instead of the intended MDMA. Methamphetamine, also known as speed, would have been expected to produce these results, they say. "We're very regretful about what it might have done, not only to our scientific colleagues, but to the public at large," Una McCann, one of the team, told the The Baltimore Sun.