Nicotine and ethanol interaction on conditioned taste aversions induced by both drugs.

The present study was designed to explore the interactive effects of nicotine and ethanol in the pretreatment and preexposure conditioned taste aversion (CTA) paradigm. The first experiment examined the effects of ethanol pretreatment on a nicotine induced CTA. The second experiment examined the effects of nicotine pretreatment on an ethanol CTA. The results of these two experiments revealed an asymmetrical interaction between ethanol and nicotine. Although nicotine pretreatment blocked an ethanol induced CTA, ethanol pretreatment merely attenuated a nicotine-induced CTA. These findings demonstrated that ethanol and nicotine interact pharmacologically in a unidirectional fashion, suggesting some unique and unshared pharmacological properties of each agent. The third experiment of this study examined the effects of preexposure with ethanol on a nicotine-induced CTA, while the fourth experiment examined the effects of preexposure with nicotine on an ethanol-induced CTA. These results revealed a symmetrical interaction between ethanol and nicotine in that both agents equally blocked CTA to one and the other. In contrast to the pretreatment CTA paradigm, these results suggested that both ethanol and nicotine appear to be functionally related and share common stimulus properties. Taken together, the present study demonstrates that while ethanol and nicotine are functionally related, they may also be endowed with unique unshared properties.