The effect of Delta9-tetrahydrocannabinol (THC) on the establishment and the expression of place conditioning (Rattus norvegicus)

The place conditioning paradigm has been used to assess the antinausea potential of drugs in non-emetic animal species. The present experiments were designed to determine the potential of A9-tetrahydrocannabinol (THC) to alleviate both conditioned and unconditioned sickness in rats (Rattus norvegiens). The results in the present study suggest that when the place aversion is strong (Experiment 1), THC may interfere with the establishment; however when the aversion is weak (Experiments 2 and 3), THC may interfere with the expression. Also, when administered during acquisition of a strong amphetamine-induced place preference, THC also seems to interfere with the establishment of the preference. Therefore it appears that when the place association is strong, THC may interfere with the associative process itself, but when the place association is weak THC may interfere with the conditioned sickness or the retrieval of the association