Abstract

Responding in patas monkeys was maintained under a multiple schedule of food presentation. One component of the multiple schedule was a repeated-acquisition task in which the discriminative stimuli for left- and right-key responses changed each session (learning). In the other component, the discriminative stimuli were the same each session (performance). The mixed agonist-antagonists dezocine, GPA 1657 and nalbuphine each produced dose-related decreases in the overall rate of responding in each component of the multiple schedule. In general each drug produced greater rate-decreasing effects in the learning than in the performance component, although this differential effect between components was less apparent with dezocine. In the learning component low doses of nalbuphine and GPA 1657 produced small increases in percentage of errors but had little or no effect on response rate. A similar effect was obtained with dezocine in only one of four subjects tested. At doses which produced comparable rate-decreasing effects dezocine also exerted the least disruptive effect on the within-session pattern of acquisition. High doses of each drug disrupted accuracy in each component of the multiple schedule. In contrast to the other drugs tested, buprenorphine had virtually no effect on response rate or percentage of errors in either component of the multiple schedule across a wide range of doses (0.01-3.2 mg/kg). The results suggest that, among the mixed agonist-antagonist, buprenorphine is unique in that it does not disrupt the acquisition or performance of complex discrimination in patas monkeys.