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Lasting influence of social hierarchy on impulsivity and cocaine choice in cynomolgus monkeys
Author(s) -
Czoty Paul W.,
Gould Robert W.,
Nader Susan H.,
Nader Michael A.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a781-d
Subject(s) - impulsivity , psychology , dominance hierarchy , social relation , developmental psychology , aggression , social psychology
Position in the social dominance hierarchy influences brain function and sensitivity to cocaine. This study examined the effects of social reorganization and assessed whether impulsivity predicted new social rank and cocaine choice. Twenty‐four male cynomolgus monkeys were used, 12 of which had previously been group‐housed for more than 3 years. Monkeys were reorganized into 6 groups consisting of 4 previously dominant, 4 previously subordinate or 4 previously intermediate‐ranked monkeys, plus 3 groups of previously singly housed monkeys. Monkeys were individually housed for several months before reorganization, during which time impulsivity was assessed by placing an opaque box into each monkey’s home cage. Latency to touch the box was recorded: the shorter the latency, the more “impulsive” the monkey. Latencies did not predict new social rank, but were influenced by previous social rank, such that the 5 least impulsive monkeys were previously dominant. Once hierarchies stabilized, monkeys self‐administered cocaine under a concurrent schedule of food and cocaine (0.003–0.56 mg/kg/injection) availability. Like impulsivity, cocaine choice was influenced by previous rather than current social rank. These results indicate that exposure to social variables has long‐lasting effects on behavior and sensitivity to cocaine in monkeys. Support: DA 10584.