Appetitive and Consummatory Sexual Behaviors of Female Rats in Bilevel Chambers

Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist

“…Solicitation and hops and darts are appetitive precopulatory sexual behaviors that female rats use to arouse males (14). Females that solicit and pace their copulatory contact receive vigorous copulatory stimulation from males at a desired interval, thus increasing the likelihood of pregnancy (15).…”

“…This is due, in part, to a concentration on the lordosis reflex as the defining characteristic of sexual behavior in female rats. Although lordosis is critical for vaginal intromission, and indicates that the female is receptive to such stimulation, it accounts for only one aspect of the behavioral pattern exhibited by females during copulation (14). Moreover, there is no human counterpart to lordosis as a measure of sexual receptivity.…”

“…Other behaviors displayed by female rats during copulation are divided between solicitations and pacing, behaviors that allow females to initiate and regulate the timing of sexual contact. Indeed, hops and darts are also used by female rats to entice males to mount (14,15,23), and those behaviors were increased after PT-141 treatment. To the extent that appetitive measures of sexual activity in female rats are analogous to sexual desire in women (24), we conclude that PT-141 has the behavioral properties expected of a pharmacological aid in the treatment of sexual desire disorders.…”

“…Ovariectomized Long-Evans rats received 10 preliminary tests of sexual behavior in bilevel or unilevel pacing chambers with sexually vigorous Long-Evans male rats before tests with PT-141. This was done to acclimate the females to the handling and testing procedures, and has been shown previously to induce stable baseline rates of sexual behavior (14). Tests were conducted at 4-day intervals during the middle third of the rats' dark circadian cycle.…”

“…Given the prevalence of sexual arousal and desire disorders in women (13) and the lack of available pharmacological treatments, we asked whether PT-141 might facilitate appetitive aspects of sexual behavior in the female rat. Accordingly, the present study examined the doseresponse effects of PT-141 on proceptive sexual behaviors, such as solicitation, hops and darts, and pacing, and receptive sexual behaviors, such as lordosis, in ovariectomized female rats tested under different hormone priming regimens in bilevel chambers (14) and unilevel pacing chambers (15,16) (shown in Fig. 1).…”