Only self-paced mating is rewarding in rats of both sexes

When rats are mated in a traditional mating chamber (with one male and one female) in which the male dictates the pace of the copulatory sequence, mal es develop a reward state as evaluated by conditioned place preference (CPP ). In this mating situation no reward state is induced in females. However, when female rats are able to control (pace) the rate of sexual stimulation , thereby reducing the aversive consequences associated with mating, a clea r CPP is observed. In the present study the CPP paradigm was used to determ ine whether if the reinforced state induced by coital interactions in male rats can be maintained when females pace the sexual interaction. Adult male and female rats were mated in one of two different conditions: (1) where s ubjects were able to pace their coital interactions or (2) where subjects w ere not able to pace their sexual contacts. The results showed that when ma les had control over the sexual interaction they developed a clear place pr eference while males that mated with females that paced their coital contac ts did not develop CPP. Similarly, only females that were able to pace thei r sexual contacts developed place preference. These results suggest that co ital interactions in males, as well as in females, can induce a reward stat e only when they are able to control the sexual interaction. Under seminatu ral conditions sexual behavior in rats is highly promiscuous, they mate in groups and repeatedly change partners in the middle of copulation. This beh avioral sequence allows both, male and female to control the rate of sexual interaction, assuring the induction of a reward state outlasting the actua l performance of coital responses. (C) 2001 Elsevier Science.