The role of conditional drug responses in tolerance to the hypothermic effects of ethanol.

The role of predrug cues in tolerance to ethanol-induced hypothermia was investigated in two experiments. The results of Experiment 1 demonstrated that tolerance was displayed only when the drug was administered in conjunction with environmental stimuli that had, in the past, accompanied ethanol administration. A conditional hyperthermic response was elicited when a placebo, instead of ethanol, was administered in conjunction with the usual ethanol cues. Results of Experiment 2 suggested that tolerance to ethanol-induced hypothermia can be extinguished by repeated placebo injections. These results indicate that associative processes, previously demonstrated to modulate opiate tolerance, also modulate ethanol tolerance.