Cognitive deficits associated with chronic cocaine self‐administration in monkeys

Abstract

In humans, cocaine dependence is associated with neurobiological, behavioral, and cognitive deficits when compared to non‐drug abusers. In monkeys, cocaine self‐administration (SA) induces similar neurobiological changes, yet cocaine‐induced cognitive deficits have not been extensively studied. We compared cognitive performance using CANTAB touch‐sensitive computer apparatus to assess measures of learning, memory and behavioral flexibility in age‐matched experimentally naïve rhesus macaques (n=4) and monkeys with a >5 year (>1.5 g/kg lifetime intake) cocaine SA history (n=4). Preliminary data suggests monkeys with a cocaine SA history require a greater number of trials to acquire stimulus discrimination and reversal and set shifting tasks (intradimensional/extradimensional shift). Similar response and reinforcer retrieval latencies across trials suggest differences are not a result of deficits in motor coordination or reinforcer devaluation compared to cocaine. Previous studies demonstrating specific CNS structures responsible for accurate performance on these tasks suggest cocaine SA is associated with deficits in prefrontal and orbitofrontal cortical activity, consistent with neurological assessments in human studies. Future studies will examine the ability of potential treatment medications to improve cognitive declines associated with chronic cocaine use. DA10584, DA06634.