Rearing paradigm in a nonhuman primate affects response to beta-CCE challenge.

Two groups of socially housed rhesus monkeys were raised under conditions differing in the degree of control or mastery over appetitive stimuli (food, water, and treats) in the 1st year of life. At age 18-24 months, a benzodiazepine receptor inverse agonist, beta-carboline-3-carboxylic acid ethyl ester (beta-CCE), was administered to both social groups to investigate the effects of differential rearing on the response to a putative anxiogenic drug. In both groups beta-CCE was followed by behavioral activation with a profile suggesting increases in aggression rather than fear or anxiety. A group by drug analysis revealed that the increase in aggression was observed predominantly in the subjects reared with mastery during the 1st year. Plasma cortisol increased in both groups, but its increase was greater in the yoked subjects. These results suggest that early experience with controllability may have long term consequences which can be revealed by challenge with beta-CCE.