INFLUENCE OF FEMALE COPULATORY-BEHAVIOR ON THE INDUCTION OF PSEUDOPREGNANCY IN THE FEMALE RAT

Female regulation of inter-intromission intervals and the successful induction of pseudopregnancy were investigated. Three groups of intact female rats received 5, 10 or 15 intromissions, respectively, in a two-compartment escape-re-entry mating arena in the presence of three sexually vigorous males. Three additional groups of intact females received 5, 10 or 15 intromissions in the same arena but were not allowed access to the escape platform and thus were not allowed to pace their sexual contacts. Five intromissions were sufficient to induce pseudopregnancy in a majority of females allowed to pace their sexual contacts, as compared with females in the no-escape condition. With increasing numbers of intromissions (10 and 15 intromissions) pseudopregnancy was seen in a majority of females in both the escape and no-escape conditions. Inter-intromission intervals were extended for all escape groups. The results demonstrate that female regulation of the temporal receipt of intromissions contributes a complementary behavioral component to the mating sequence which can potentiate the stimulation of intromissions by the male. © 1979.