Differential effects of chlordiazepoxide on comparable rates of responding maintained by food and shock avoidance

Comparable rates and patterns of lever-pressing by rats were obtained under a multiple variable interval schedule of food reinforcement and continuous shock avoidance. Chlordiazepoxide (1.0--17.0 mg/kg) produced increases in food maintained responding at doses that decreased avoidance responding. Removing food, shock, or both in separate individual probe sessions did not produce differential effects. Under certain circumstances, the effects of chlordiazepoxide appear to be best predicted by knowledge of maintaining conditions.