Effects of in utero cocaine exposure on cocaine‐food delay discounting procedures in adult rhesus monkeys

Abstract

This research examines the behavioral and neuropharmacological consequences of in utero cocaine (COC) exposure in adult male and female rhesus monkeys. Previous data from our laboratory found that monkeys exposed to cocaine in utero acquired cocaine self‐administration more rapidly under a simple fixed‐ratio schedule of reinforcement and, under concurrent food‐food schedules, display a preference for smaller, non‐delayed food reinforcers relative to the larger delayed reinforcers compared to controls. In this study, we extended these findings to a cocaine‐food delay discounting procedure. Under baseline conditions, COC (n = 8) and control (n = 7) monkeys chose between cocaine (0.001–0.3 mg/kg) and three 1‐g food pellets; COC monkeys preferred cocaine to food at lower doses compared to controls. When delays (5–300 sec) were associated with cocaine choice, the indifference points (ED50 values) were similar for both groups (~ 120 sec). However, COC monkeys were highly variable – half were well above 120 sec and the others well below. Compared to food‐food delay discounting, control monkeys ED50s were similar, while COC monkeys had lower food values (~ 65 sec). These findings suggest in utero cocaine exposure may make adults less sensitive to contingency changes involving cocaine relative to non‐drug reinforcers, which would be problematic for contingent management treatment strategies. DA025120