Abstract # 219:

Scheduled for Saturday, August 19, 2006 10:15 AM-10:30 AM: Session 21 (Regency East #3) Oral Presentation


THE IMPACT OF INFANT MALTREATMENT ON BEHAVIORAL AND PHYSIOLOGICAL RESPONSES TO THREATENING STIMULI IN RHESUS MONKEYS: SEX DIFFERENCES

A. P. Grand1,2, K. M. McCormack2,3, M. E. Kelley4, D. Maestripieri2,5 and M. M. Sanchez2,4
1University of Georgia, Dept of Psychology, Athens, GA, USA, 2Yerkes National Primate Research Center, 3Spelman University, 4Emory University, 5University of Chicago
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     We investigated the long-term effects of infant maltreatment on behavioral and hypothalamic-pituitary-adrenal (HPA) axis reactivity of rhesus macaques (Macaca mulatta) to novel stimuli. Ten maltreated and ten non-maltreated, 2-year old rhesus macaques were exposed to novel neutral objects, fear-evoking objects, and a human intruder, during three separate videotaped sessions, a week apart. Immediately following the exposures, 2 ml of blood was collected for neuroendocrine analyses. Latencies to touch, bite, and inspect the objects were measured, and rates of freezing, locomotion and aggressive/submissive behaviors. Responses to the stimuli varied depending on the sex and maltreatment history of the animal. There was a maltreatment by sex interaction for the latency to touch and inspect fear-evoking objects (F=4.463, F =4.212, p=0.05), with abused males exhibiting shorter latencies than controls. During the fear-evoking object exposure, maltreated females were more defensive and submissive than control females (Chi-square=6.00, Chi-square= 4.00, p<0.05), while maltreated males were more aggressive toward stimuli than control males (Chi-square= 4.80, p<0.05). Although there were no group or sex differences in cortisol or ACTH responses, correlations between the HPA axis and behavioral responses to the tests were found. These results indicate long-term effects of infant maltreatment on behavioral reactivity to novel stimuli, different in males than in females. [Support: ASP Small Grant, NIMH grants MH01005 (MMS), MH62577 (DM), RR00165].