Power has its perks, even for laboratory-housed monkeys. When moved from individual to group cages, socially dominant male monkeys exhibit a brain-chemistry change that fosters resistance to using drugs such as cocaine, a new study finds.
This alteration increases the amount of so-called dopamine D2 receptors, a molecular gateway on brain cells controlled by the chemical messenger dopamine.
Earlier studies implicated these receptors in pleasurable responses to drugs and other stimuli.
In contrast, male monkeys at the bottom of the social pecking order display no boost in the D2 receptors when housed with other monkeys, say neuroscientist Michael A. Nader of Wake Forest University School of Medicine in Winston-Salem, N.C., and his colleagues. Unlike their more dominant cage mates, the low-ranking monkeys readily self-administer large amounts of cocaine.