In a recent study in mice, pain made a female mouse significantly less interested in mating no matter where the pain was: in the tail, genitals, cheek or hind legs. The male mice still sought to copulate with females even if in pain, whether in the penis or other parts of the body.
Scientists tested sexual motivation in mice by putting the male and female mice in a mating chamber and divided them with a barrier with openings that were too small for the males to get through but big enough for the females if they wanted to get closer to the males.
Researchers also studied the sexual drive of male mice by putting them in a chamber with no dividers and unlimited access to the females. Both male and female mice were injected with substances that caused inflammatory pain in their tails, hind legs, cheeks and genitals. When the female mice were given painkillers or libido-enhancing substances, the effect of the pain lowering their libidos was reversed.
Concordia University and McGill University researchers previously investigated the impact of pain on the sexual behavior in mice.
"We know from previous studies that women's sexual desire is far more dependent on context than men's, but whether this is due to biological or social cultural factors, such as upbringing and media influence, is not known," said McGill psychology professor and study author Jeffrey Mogil said.
Researchers said human sexual desire might have a similar biological, instead of cultural or social mechanism as the mice. The study provides clues on how the female libido works amidst the belief that sexual desire in women is based mainly on cultural expectations.
"Since giving birth and raising babies have costs associated with it, you might expect that the female mice would -- or at least their genes would want them to -- make sure that they are in pretty good shape," Mogil said. Pain could be a sign that the female mice are "not in perfect health and it might not be a good idea to have babies right now." He also said that males are only concerned about getting through conception and their job is done.
Loss of libido usually occurs in humans with chronic pain. This study reinforced the findings and may even help for further investigations on potential libido-enhancing drugs. It was published in the Journal of Neuroscience.
