Mating Behavior of Rats Bred for High- and Low- Saccharin Intake.

Abstract

Emotional adaptation to stressful situation of mating is an area of that has not been adequately studied. Rats selectively bred for saccharin intake differ in emotionality. Low-saccharin affinity rats (LoS) are more easily agitated and excitable; high saccharin rats (HiS) calmer and less emotionally labile. In this study, ten couples, five couples from each saccharin line, were observed for frequency of certain social signals and reproductive behaviors, such as rearing, mounting, and lordosis. Receptive females were placed in a breeding arena with a male from the same line and videotaped for ten minutes. Videos were scored based on operationalized behavioral criteria by two blind raters. Rats displayed line differences in rearing with the LoS rats rearing more frequently. Sex differences, independent of line differences, showed that males reared less than females, took longer to initiate the smelling encounter, and smelled their mate more overall. The videos of eight other couples (four HiS and four LoS) are in the process of being scored. Some behaviors that have not shown significance with the current number of subjects are expected to increase in significance when these couples are added to this study.