Change to sensory organ in nose gives females a male sex drive

WASHINGTON (Reuters) - Female mice became sexually voracious and tried to mate like males after scientists disabled a small sensory organ, casting fresh light on how gender-specific behavior develops in animals.
The difference seems to lie in how male and female mice use the vomeronasal organ to process pheromones, said Catherine Dulac, the Harvard biologist who led the research published in the journal Nature Sunday.
Pheromones are chemical signals that many animals, including humans, use to communicate socially and sexually.
The vomeronasal organ, found in the noses of some animals but not in people or higher primates, is a key processing center for pheromones.
Scientists had long attributed aggressive male mating tactics to a testosterone-induced hard-wiring of male brains.
"Here you have females that never had male hormones but have perfectly male behavior," Dulac said in a telephone interview.
In female mice, pheromones normally suppress male sex behaviors and activate female ones, the research suggests.
"This comes as a surprise to think that the neural circuitry for male behavior had been sitting in the female brain all this time," said Mark Breedlove, a neuroscientist at Michigan State University not involved in the study.