Interactions of testosterone with the olfactory system in the display of mounting behavior in the female rat

Adult ovariectomized female rats received a testosterone propionate (TP) silastic implant (day 0) and were subsequently tested for mounting behavior. The number of females displaying mounting behavior increased from day 2 (0%) to day 14 (94%) following testosterone implantation. Olfactory bulbectomy (OB) performed on day -7 or on day +14 reduced the number of females that mounted on day +16 as compared to sham counterparts. However, the number of females displaying mounting behavior was significantly higher when OB was performed on day +14 than on day -7. Peripheral anosmia induced by ZnSO4 instillation, either with multiple instillations beginning on day -8 before TP implant or with a single injection on day +14, equally impaired mounting behavior on day +16. These results, which further confirm the role of the olfactory system in facilitating the display of mounting behavior in the female rat, suggest an olfaction-testosterone interaction.