'Love Hormone' Utterly Rules Female Sexual Attraction

A new study has shown that the "love hormone" known as oxytocin may be the primary, if not sole, determinant of whether or not an animal feels sexual attraction towards a prospective mate. Interestingly, this only seems to hold true for females.

The study, recently published in the journal Cell, details how female mice deprived of oxytocin were no more attracted to prospective mates than they were attracted to a LEGO block.

"This internal hormone gets regulated in many different contexts; in this particular context, it works through the prefrontal cortex to help modulate social and sexual behavior in female mice," study co-author Nathaniel Heintz, of Rockefeller University, recently explained to BBC News.

Oxytocin is traditionally viewed as the "love hormone" because it is released in intimate moments such as during kissing, sex, and even childbirth. Researchers have found that it helps facilitate lasting bonds and may even help people be more accepting of other people and behaviors. New research has even suggested that the hormone as a supplement can help people with eating disorders become more accepting of their own bodies with the right therapy.

Now it is being argued that the hormone is a fundamental part of the mate selection process.

According to the study, researchers took several female lab mice and "silenced" neurons in the prefrontal cortex of the brain that contain receptors for oxytocin. The mice were then presented with several prospective mates - including a LEGO block - during oestrous, which is when female mice are normally sexually active.

The oxytocin-deprived females were found to be utterly disinterested in sex or the males' advances. Interestingly, once oestrous was over, they otherwise interacted with the males and plastic block as they normally would.

But this does not have the same effect on male mice. The researchers believe that female cells were more responsive to the hormone than the equivalent cells in male mice.

"These circuits may exist similarly in other species, including humans, so understanding these circuits we found in mice might help us to understand why oxytocin has these effects in humans, too," Heintz added.