Classical conditioning and caffeine tolerance: the importance of drug-associated environmental cues to the development of tolerance to stimulatory behavior in rats

Hilary Jean Hicks, The College of Wooster


Caffeine's stimulation of locomotor activity is subject to tolerance, which has most often been explained with a physiological model. However, according to Shepard Siegel's model of conditioning and tolerance, the environmental cues that are present during drug administration eventually become associated with the drug's physiological effects. These environmental cues come to elicit compensatory responses that are opposite to the drug's effects, so when paired, the drug's physiological effects are attenuated, which is tolerance. Sprague Dawley rats were given a chronic administration of caffeine in their drinking water for ten days and subjected to open field and emergence testing. On the last day of behavioral testing, they were given caffeine in a new environment not previously associated with drug administration. Although the results do not provide support for Siegel's model, they do contribute to the literature regarding caffeine-induced behavior. Caffeinated rats were significantly more active and impulsive throughout the experiment.