SOME EFFECTS OF COCAINE AND 2 COCAINE ANALOGS ON SCHEDULE-CONTROLLED BEHAVIOR OF SQUIRREL-MONKEYS

Abstract

The behavioral effects of 2 phenyltropane cocaine derivatives were compared with those of cocaine. Squirrel monkeys responded under multiple fixed-interval [FI], fixed-ratio [FR] schedules of either stimulus-shock termination or food presentation or under a FR schedule of food presentation. The 3 drugs effects were independent of the type of event that maintained responding. Under the FI schedules, some doses of each drug increased responding, whereas larger doses generally decreased responding. Maximal increases in responding were similar with each drug. Appropriate doses of each drug increased low response rates, which occurred during the initial segments of the FI but had little effect on or decreased higher response rates, which occurred during the later segments of the FI. Under the FR schedules, each drug decreased responding in a dose-related manner. Decreases in FR responding resulted both from increased periods of no responding at the beginning of the FR and from decreased rates of responding once responding began. Each cocaine analog had a slower onset of effect and a longer duration of effect than cocaine. The behavioral effects of the 2 cocaine analogs were qualitatively similar to those of cocaine but each was 3-10 times more potent than cocaine.