The partner preference paradigm: a method to study sexual motivation and performance of female rats

Sexual behavior of the female rat consists of initiative, as well as receptive components. Previous studies on female sexual behavior have focused on the reflexive response to a male's mount, i.e., the lordosis reflex, whereas the initiative and soliciting gestures that are exhibited by the female during copulation were ignored by most researchers. This bias led to a misconception of the female's role in the sexual act, according to which the female is passive and submissive, whereas the male rat is sexually dominant or even aggressive. In this paper, we describe a procedure, the partner preference paradigm, designed to investigate and quantify sexual motivation, initiation and solicitation in female rats. In this paradigm, the female can control the sexual act because the mobility of her sexual partner is limited. This setting enables to measure a variety of soliciting behaviors that reflect the active seeking of sexual contact by an estrous female. In addition, this paradigm enables the evaluation of the females' motivation to engage in a sexual act, by measuring the preference for a sexually appropriate over an indifferent partner. Moreover, the partner preference paradigm may be easily adopted for studies in male subjects, allowing the comparison of males' and females' responses to various experimental conditions.