Researchers have created mice that apparently are able to avoid the addicting effects of cocaine. In a study published in Nature Neuroscience genetically engineered mice were given the drug multiple times, but didn't appear to cave in to the drug the way other mice do. The reports says mice didn't go back to the room where they received the cocaine and stayed in their cages.
NPR reports the mice were genetically engineered to produce high levels of proteins in the brain's "reward circuit." The study says the proteins blocked the brain's usual tendency to associate a place with a cocaine high.