Effects of Ethanol on Stimulus Properties of D-Amphetamine

The drug discrimination paradigm was used to investigate the effects of combinations of d-amphetamine sulfate (amph) and alcohol (etoh). Rats were trained to discriminate between the stimulus properties of 1.2 mg/kg amph and non-drug treatment in a two-lever food-motivated operant task. Once trained, rats were tested with .3 mg/kg amph, and showed an intermediate level of "amphetamine" responding. Combinations of this test dose with etoh 150 mg/kg or 300 mg/kg produced significantly increased amph-appropriate responding. This potentiation of the amph cue tended to be higher at etoh 150 mg/kg. The administration of etoh (150 or 300 mg/kg) alone did not result in amph-appropriate responding. These findings confirm earlier results from both drug discrimination and other behavioral paradigms, indicating that low doses of etoh in combination with low doses of amph can result in potentiation of amph effects.