Electronic Thesis and Dissertation Repository


Master of Science




Martin Kavaliers

2nd Supervisor

Peter Ossenkopp

Joint Supervisor


Rats, which are a non-emetic species, display conditioned disgust responses when re-exposed to a context previously associated with sickness. These conditioned disgust responses can be used to model anticipatory nausea in humans, a growing problem faced by numerous chemotherapy patients. This thesis found that social factors, in addition to contextual factors, can play a role in the expression of toxin (LiCl)-induced conditioned disgust in rats. The results show that a familiar, but not unfamiliar, social partner can serve as a cue for the display of conditioned gaping. Further, a variety of sensory cues may play a role in the development of socially-mediated conditioned disgust, as an odour cue (urine) alone was incapable of causing significant conditioned disgust. It was also found that socially-mediated conditioned disgust can be modulated by oxytocin, as an oxytocin receptor antagonist, L-368,899, significantly decreased the display of conditioned gaping. Therefore, these findings suggest that social factors can lead to the development and expression of toxin-elicited conditioned disgust responses in rats. This has implications for chemotherapy patients, as the development and expression of anticipatory nausea may also be impacted by social factors.