Fig. 1.

Effects of rh5-HTTLPR genotype (l/l or l/s), rearing condition (MR or PR), and sex (male or female) on ACTH responses to acute stress in infant rhesus macaques. (A) Values listed are mean plasma levels of ACTH in pg/ml ± SEM determined at baseline (Stress –, 2 and 6 months) and after stress (Stress +,3,4, and 5 months). (B–D) Shown are serum ACTH levels for Basal-1 (B), stress (C), and Basal-2 (D) testing conditions. During both baseline conditions, PR animals had lower levels of ACTH. After stress, there were interactions between rearing and genotype and among rearing, genotype, and sex. (*, P < 0.05; **, P < 0.01; ***, P < 0.005).