" src="https://www.babymed.com/%3Ca%20href%3D"http://www.babymed.com/sites/all/modules/wysiwyg/plugins/break/images/spacer.gif">http://www.babymed.com/sites/all/modules/wysiwyg/plugins/break/images/sp..." alt="<--break->">Mice in laboratoryWhen women are in pain, they’re not often interested in sex. A team of Canadian researchers wanted to know more about how pain affects libido. They were interested in learning if the lack of desire is learned, social, cultural, mental, imaginary, or maybe hard-wired by biology or evolution. They found that, yes, chronic pain dampens the female sex drive but, no, it doesn’t stop the male sex drive at all. And they think the problem just might be evolutionary.

Melissa Farmer, now at Northwestern University in Evanston, Illinois, devised the test of pain and libido when she was earning her PhD at McGill University in Montreal, Quebec. Farmer used male and female mice in specially constructed chambers for her study.

Female Pain Test

Farmer injected substances known to cause pain and inflammation into the genitals of female mice in heat. In addition, some female mice were injected in varying combinations in a cheek, a hind paw, and their tail.

Once prepped, the female mice were placed in a chamber with two compartments. A hole in the wall separating the two compartments was small enough to allow the female mice to freely enter or leave both chambers.

A male mouse was placed in one compartment but the hole in the wall was too small to allow him move freely between compartments.

The female mice in pain didn’t spend much time with the male, even though they were in heat. The mating rate was lower than normal.

Male Pain Test

Pain was induced in male mice the same way it was in the females. The male mice were placed in an open mating chamber with an untreated female in heat. This configuration gave the males free access to mate if they chose to. They did. Pain didn’t even slow them down.

Pain Relief

When the treated female mice were given a pain-relieving drug and/or one of two libido-boosting drugs, their sex drives returned to normal. They chose to mate once pain had subsided.

Yitzchak Binik served as an advisor to Farmer for the experiment. Binik is a McGill professor of psychology and the director of the university Health Center’s Sex and Couple Therapy Service. Binik says, “Chronic pain is very often accompanied by sexual problems in humans” and feels Farmer’s study will lead to further study of “this important symptom of chronic pain.”

Jeffrey Mogil, another psychology professor at McGill who participated in the study, says the diminished sexual drive of female mice in pain suggests “an evolutionary biology explanation for these effects in humans — and not simply a sociocultural one.”

Source: Farmer, Melissa A, et al. “Pain Reduces Sexual Motivation in Female But Not Male Mice.” The Journal of Neuroscience. The Society for Neuroscience. Apr 23, 2014. Web. May 19, 2014.