When courting, male mice lacking the chemical messenger serotonin don’t seem to care whether the object of their affection is female. Mice without the neurotransmitter no longer eschew the smells of other males, wooing them instead with squeaky love songs and attempts to mount them, researchers report online March 23 in Nature.
Serotonin’s surprise role in mouse courtship may lead to a deeper understanding of how brain cells control a complex behavior.
“Nobody thought that serotonin could be involved in this kind of sexual preference,” says study coauthor Zhou-Feng Chen of Washington University School of Medicine in St. Louis.
Scientists emphasize that the male-male courtship seen in the lab isn’t equivalent to human homosexuality. And what, if anything, serotonin has to do with human sexual behavior is still an open question.