EFFECTS OF PACED MATING AND INTROMISSIVE STIMULATION ON FEMININE SEXUAL-BEHAVIOR AND ESTRUS TERMINATION IN THE CYCLING RAT

The effects of differential mating stimulation on sexual behavior and estrus length were examined in cycling rats that could or could not se lf-regulate, or pace, the timing of sexual contact. Female rats (Rattu s norvegicus) received 30 paced, 30 nonpaced, or 15 nonpaced followed by 15 paced intromissions during mating tests. Decreases in sexual res ponsiveness were seen during the second half of testing; pacing was as sociated with greater inter-intromission intervals, decreased procepti vity, and increased rejection behavior at this time. Female rats pacin g during the second test half behaved similarly, regardless of prior t reatment, showing that the number rather than the timing of prior intr omissions affected subsequent behavior. However, estrus length was dec reased by prior paced mating. These data suggest that changes in sexua l responsivity occur throughout estrus and that the nature of these ch anges is differentially dependent on the type of mating stimulation re ceived.