Spurned male fruit flies turn to alcohol

Male fruit flies deprived of sex may turn to alcohol as a source of pleasure, US researchers exploring the brain's reward system said. Scientist at the University of California, San Francisco decided to study how the reward system may be affected by a social interaction -- sex -- and how that might affect the seeking of pleasure by other means, including alcohol, The Washington Post reported Friday. Previous studies have shown alcohol consumption is a rewarding experience for fruit flies, they said. The researchers placed 24 male fruit flies in containers containing female fruit flies, some of them virgins, some of them already mated. Females that have already mated will reject a male's advances, so many males in the study were subjected to repeated rejection over the course of four days, the scientists said. Meanwhile, a second group of male fruit flies was placed in vials with virgin females who were open to their advances. The males in both groups were then allowed to choose between two food options, a plain food mash or the same food laced with alcohol. The sexually deprived males overwhelming selected the alcoholic version, drinking four times as much as their sexually satisfied counterparts, the researchers said. Researchers say mammals, including humans, have a chemical in their brains called neuropeptide Y similar to a chemical in fruit fly brains that was found to be reduced in amount in the sexually deprived fruit flies. The fruit-fly findings might therefore shed light on mechanisms behind human substance abuse and addiction, they said.