Taste aversion disruption by drug pretreatment: dissociative and drug-specific effects.

Disruption of taste aversion learning following the administration of the same drug prior to and during conditioning (intra-agent disruption) was shown to be greater than disruption following the administration of one drug prior to conditioning and another during conditioning (inter-agent disruption). Comparable dosages of ethanol and lithium chloride served as unconditioned stimuli. Inter-agent disruptions are attributed to a dissociation of conditioned and unconditioned stimuli, while intra-agent disruptions are attributed to both a dissociative effect and drug-specific effects. Intra-agent disruption was correlated with an independent measure of tolerance, suggesting tolerance constitutes at least a portion of the drug-specific effects.