Enhancement of Pavlovian Conditioned Suppression by Mild Ethanol Intoxication

Rats were trained to bar-press for food and then received aversive Pavlovian conditioning following low doses of ethanol (0-1600 mg/kg in different groups). They were tested for Pavlovian conditioned suppression of bar-pressing 48 h, 7 days, and 14 days later following no additional differential treatments. The results showed that very low doses of ethanol (approximately 200 mg/kg) during training enhanced later conditioned suppression, whereas more moderate doses (800-1600 mg/kg) disrupted Pavlovian conditioning. These results parallel earlier observations that very low ethanol doses enhance Pavlovian conditioned eyeblink and heart rate responses in rabbits, and suggest that facilitation of Pavlovian conditioning may be a general effect of mild ethanol intoxication.