Changes in fixed-ratio performance and blood alcohol levels in monkeys.

Three female Bonnet monkeys prepared with indwelling venous catheters were maintained on a fixed-ratio schedule of food reinforcement until response rates were stable. The animals were then intubated with alcohol (5.0 g/kg) 30 min prior to testing. Blood alcohol concentrations (BACs) were determined every 15 min throughout the 90-min session. Each alcohol intubation was separated by 3 days and on the second control day an isocaloric sucrose solution was intubated. The results show that the alcohol-induced response suppression gradually returns to baseline levels after 5 alcohol intubations, and the BACs were concomitantly decreased. The results indicate that the reversibility of alcohol induced behavioral impairments and changes in BACs develop within similar temporal intervals.