INTERACTION OF HUNGER AND SEXUAL MOTIVATION IN THE MALE-RAT - TIME-SHARING APPROACH

To examine the interaction of hunger and sexual motivation, male rats were given sexual behaviour tests under 0, 24, and 48 h of food deprivation. Each male was placed with an oestrous-induced female and allowed to copulate until sexual exhaustion. Food was freely available throughout the test period. Mount and intromission latencies increased under both levels of food deprivation, but neither ejaculation frequency nor any of the other fourteen measures of sexual behaviour were altered under deprivation conditions. There was a decreased latency to start eating, an increase in time spent eating, and an increase in the amount of food eaten with increased food deprivation. The frequency of feeding bouts increased, but the duration of feeding bouts was constant over deprivation conditions. Under food deprivation, animals shifted from sexual behaviour to feeding more frequently than when they were non-deprived. These shifts occurred primarily during periods of low sexual arousal. The majority of feeding occurred during the post-ejaculatory intervals. Bouts of sexual behaviour were not usually interrupted by bouts of feeding. This pattern suggests that feeding and sexual activity occur on a time-sharing basis with sexual behaviour as the dominant activity. © 1979.