Vaginal bacterial flora partially determines sexual attractivity of female rats

This study shows that the bacterial flora of the rat's vagina plays a role in the determination of female sexual attractivity. In the experiment described, the change in attractivity of a female rat was monitored during the estrous cycle by using a residential plus-maze. The time that male rats spent in the vicinity of a female rat was used as a measure of the attractivity of that female. The vaginal bacterial flora of one of these females was killed by daily injection in the vagina of an antibiotic solution. It was found that male rats preferred the company of an estrous female with an untreated vagina over the company of an estrous female with a 'sterilized' vagina. This indicates that the vagina produces an olfactory signal which plays a role in her attractivity for a male rat.