Conditioned place preference in female hamsters following aggressive or sexual encounters

Prior studies have demonstrated the utility of conditioned place preference procedures for examining the motivational or rewarding properties of behavior. The purpose of this experiment was to assess whether female Syrian hamsters would show evidence of conditioned place preference for aggression or sexual behaviors. Weekly conditioning sessions were conducted for three groups of female hamsters for 5 weeks. One group of female hamsters engaged in sexual activity with a male hamster in the gray compartment of a place preference apparatus. A second group of females experienced aggressive interactions with a male when placed together also in the gray compartment. Females in each of these conditioning groups were placed alone in the white compartment within 1 h of the behavioral interactions. A control group of hormone-treated females was placed alone in both compartments of the apparatus. Following the conditioning sessions, all females were given free access to the conditioning apparatus. Females with prior sexual or aggressive experience spent significantly more time in the gray compartment than they did before conditioning. Control females did not show any significant change in their preference for either compartment of the apparatus. The results suggest that female hamsters prefer an environment associated with the prior rewarding properties of sexual or aggressive interactions.