Caffeine: Sex Potion for Females?
Study: After a Shot of Caffeine, Female Rats Sought More Sex
A Large Latte's Dose of Caffeine
The researchers tested several caffeine doses on the rats. The doses were based on the rats' weight. Interestingly, the female rats that received the middle dose of caffeine had quicker return visits to the males than the highest dose tested.
Using the same formula for humans, the lowest dose would roughly equal the caffeine in "a grande latte at Starbucks ... a pretty high-caffeinated beverage, but not something outrageous," Guarraci says.
The higher doses were like having several large lattes at once, she says. Were the rats totally wired by the caffeine? "No," Guarraci says.
Her study shows that the caffeinated females didn't just skitter around their cages aimlessly. Instead, they specifically sought a male sex partner and weren't particularly interested in socializing with another female rat.
The caffeinated females seemed motivated to seek sex, not to burn extra energy from the caffeine, the researchers write.
Do You Mate Like a Rat?
Rats and humans are obviously different. But rats' elaborate courtship behavior may sound familiar to some people.
"The female seems to control the mating encounter," Guarraci says of rats.
"So when a male and a female rat are ready to mate, the female does all the gatekeeping for the male. She decides when it's time for him to mate, in the wild as well as in the lab," Guarraci says.
"The female, when she's interested, she'll go visit a male. But then when she's not interested in him anymore or wants to take a break, she runs away. To me, it seems a little bit like the playing hard-to-get with the male rats," she continues.
Ultimately, Guarraci and colleagues want to identify the chemistry and brain structures involved in sexual motivation for mammals, which include people, as well as rats.
"There are a lot of women out there with sexual dysfunction, and if they understood how that happens or how we can augment that, that would be a helpful thing," Guarraci says.