Vaginocervical Stimulation Inhibits Female–Female Mounting in Laboratory Rats

The objective of this study was to examine how vaginocervical stimulation (VCS) affects female–female mounting in laboratory rats. After receiving sexual stimulation from the male, the latency for the female to mount another female was significantly longer than that of control females. In the absence of any copulatory stimulation, the latency to initiate mounting of another female was about 3 min. However, following three mounts or three intromissions by a male, the latency for the experimental female to initiate mounting increased to about 10 min, and ejaculation abolished mounting for almost 2 h. Once females began mounting, regardless of the copulatory stimulation they received prior to testing, their mounting rate (mounting frequency/2 h) did not differ from stimulus control females. Artificial VCS also inhibited female mounting and anesthetization of the vaginocervical area diminished the inhibiting effect of ejaculation. Taken together, the present results provide evidence that VCS can temporarily inhibit female mounting, and that the duration of the inhibition is related to the amount of VCS received. These data are interpreted within the perspective that female mounting behavior is not a sexual behavior and is consequently suppressed within the context of normal copulation.