What do female rats like about sex? Paced mating

The motivational aspects of female sexual behavior have been evaluated by a variety of methodologies including: the increasing barrier method, the run way procedure, partner preference test, operant behavior and conditioned pl ace preference. When female rats an tested for sexual receptivity under tra ditional laboratory conditions, usually a small open area? both appetitive and aversive components of the sexual interaction are easily observed. For example, after prolonged testing, subsequent lordosis and the intensity of this response are reduced increasing the rejection behavior by the female. However, when female rats are allowed to pace (control) the rate of sexual stimulation they received, as usually occurs under seminatural and natural conditions, the aversive properties of mating are reduced. The conditioned place preference can be use to measure the positive affect elicited by mati ng. We have combined pacing and conditioned place preference in an attempt to reduced the possible aversive consequences associated with mating and in crease the likelihood of detecting the appetitive effects of coital interac tion in female rats. Only female rats that regulated (paced) their coital i nteractions with a stud male through a two-compartment chamber in which onl y the female could freely move from one compartment to the other developed a clear place preference. As well, females that received ten or 15 paced in tromissions (without ejaculation) also developed place preference. The plac e preference induce by paced mating is blocked by the systemic administrati on of naloxone suggesting that opioids are involved in the reward processes associated with paced mating. Paced sexual interactions can induce a posit ive affect of sufficient intensity and duration to induce conditioning. (C) 1999 Elsevier Science B.V. All rights reserved.