SIMULTANEOUS CONDITIONING OF ANTICPATORY NAUSEA AND TASTE AVOIDANCE AND THE INFLUENCE OF IMMUNE SYSTEM STIMULATION

Immune system stimulation with lipopolysaccharide (LPS) elicits a specific set of physiological and behavioral responses termed “sickness behavior”. LPS treatment has been found to impair learning and memory in a variety of learning paradigms, including those for anticipatory nausea and conditioned taste avoidance. Traditional conditioning paradigms typically employ a single conditioned stimulus (CS) and unconditioned stimulus (US). This thesis used an intravascular (intraperitoneal) saccharin “taste” cue, together with the toxin LiCl, given immediately prior to anticipatory nausea context conditioning, in order to simultaneously condition responses to both internal (taste) and external (context) conditioning stimuli. The effects of LPS on the simultaneous acquisition of anticipatory nausea and taste avoidance were then examined. In addition to the establishment of a concurrent conditioning model, the present findings suggest that LPS pre-treatment was effective in disrupting both conditioned nausea and taste avoidance