Cognitive performance and homecage activity in female cynomolgus monkeys: relationship to social rank and cocaine reinforcement (848.1)

Abstract

Nonhuman primate social groups, which represent a continuum of experiences from environmental enrichment in dominant monkeys to chronic social stress in subordinates, have been used to study susceptibility and resilience to human diseases. We have shown that social rank influences sensitivity to cocaine and other dopaminergic drugs. However, it is not clear what biological and environmental factors determine what rank an individual monkey will attain. In females, novel object reactivity and CSF concentrations of 5‐HIAA predicted social rank; these factors did not change after hierarchies stabilized. The present studies examined whether other variables, including cognitive function (using CANTAB touchscreen software) and activity (using Actical monitors), predict eventual social rank and change after social hierarchies stablized. Prior to social housing 4 monkeys per pen, performance on a cognitive task was not different in eventual dominant and subordinate monkeys. After stable hierarchies were formed, subordinate monkeys demonstrated cognitive impairments. Furthermore, future subordinates had higher activity during the day which remained higher after hierarchies stabilized, and preliminary results suggest rank differences in nighttime activity. Additionally, the relationship between these behaviors and cocaine reinforcement is being investigated. Understanding behavioral phenotypes and individual differences in response to environmental manipulations, such as attainment and occupation of social ranks, and the relationship to cocaine self‐administration will aid in the development of behavioral and pharmacological treatment strategies for drug addiction.Grant Funding Source: Supported by DA017763