Immediate and Long-Term Effects of Tibial Nerve Stimulation on the Sexual Behavior of Female Rats

Objectives There are limited treatment options for female sexual dysfunction (FSD). Percutaneous tibial nerve stimulation (PTNS) has shown improvements in FSD symptoms in neuromodulation clinical studies, but the direct effects on sexual function are not understood. This study evaluated the immediate and long-term effects of PTNS on sexual motivation and receptivity in a rat model of menopausal women. Our primary hypothesis was that long-term PTNS would yield greater changes in sexual behavior than short-term stimulation. Materials and Methods In two Experiments, after receiving treatment, we placed ovariectomized female rats in an operant chamber in which the female controls access to a male by nose poking. We used five treatment conditions, which were with or without PTNS and no, partial, or full hormone priming. In Experiment 1, we rotated rats through each condition twice with behavioral testing immediately following treatment for 10 weeks. In Experiment 2, we committed rats to one condition for 6 weeks and tracked sexual behavior over time. We quantified sexual motivation and sexual receptivity with standard measures. Results No primary comparisons were significant in this study. In Experiment 1, we observed increased sexual motivation but not receptivity immediately following PTNS with partial hormone priming, as compared to priming without PTNS. In Experiment 2, we observed trends of increased sexual receptivity and some sexual motivation metrics when PTNS was applied long-term with partial hormone priming, as compared to hormone-primed rats without stimulation. Conclusions PTNS combined with hormone priming shows potential for increasing sexual motivation in the short-term and sexual receptivity in the long-term in rats. Further studies are needed to examine variability in rat behavior and to investigate PTNS as a treatment for FSD in menopausal women.