EFFECTS OF INTRAVENOUS COCAINE ON FOOD MAINTAINED BEHAVIOR IN MONKEYS

Abstract

Two Macaca mulatta and 1 Macaca java monkeys were trained to press a key for food pellets on a differential reinforcement of low rate (DRL) schedule which required consecutive key-press responses to be spaced at least 20 s apart in order to produce reinforcement. When behavior had stabilized, the monkeys were administered either 0.0, 0.05, 0.10, 0.25 or 0.50 mg/kg of cocaine i.v. during daily sessions. Cocaine produced a bi-component, dose-dependent effect. Immediately following cocaine infusion there was a dose-related complete cessation of responding which began and ended abruptly. Following this post-infusion pause, a dose-related behavioral disruption in the form of shortened inter-response times was observed.