Abstract # 43:

Scheduled for Thursday, June 17, 2010 07:00 PM-09:00 PM: Session 11 (Medallion Ballroom C/D/E/F) Poster Presentation


INFLUENCES OF MU-OPIOID RECEPTOR AND TPH2 GENOTYPES ON HPA AXIS ACTIVITY AND SOCIAL BEHAVIOR IN DIFFERENTLY REARED MONKEYS ACROSS THE FIRST TWO YEARS OF LIFE

A. M. Dettmer1, M. A. Novak2, J. S. Meyer2, E. J. Vallender3, G. M. Miller3 and S. J. Suomi4
1University of Pittsburgh, Department of Psychiatry, Pittsburgh, PA, USA, 2University of Massachusetts, Department of Psychology, Amherst, MA, 3New England Primate Research Center, Harvard Medical School, Division of Neurochemistry, Southborough, MA, 4Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD
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Past studies have identified the influences of mu-opioid receptor (OPRM1) and tryptophan hydroxylase-2 (TPH2) geneotypes on HPA axis activity and behavior in adult monkeys (Chen et al., 2006; 2009). Elucidating these relationships in young monkeys could provide valuable insight into the development of human pathologies. We studied infant monkeys [M. mulatta, N=45] from 1-24 months who were mother-peer-reared (MPR; n=13), peer-reared (PR; n=15), or surrogate-peer-reared (SPR;n=17) and genotyped for OPRM1 (CC, n=28 or CG/GG, n=17) and TPH2 (Hap1: ACS/ACS, n=12; Hap2: ACS/AAS or ACS/GAL, n=19; Hap3: AAS/AAS, AAS/GAL, or GAL/GAL, n=14). Hair cortisol and behavioral measures were collected as previously described; age and rearing effects were presented previously (Dettmer et al., 2009). Repeated measures ANOVA revealed that Hap3 infants, which are predicted to have higher serotonin levels, had higher hair cortisol [F(2,20)=3.96, P=0.036] across development. Combined with the CC genotype, which results in higher plasma cortisol, Hap3 infants showed higher hair cortisol following a major life stressor at 12 and 18 Mos. [F(6,60)=2.65, P=0.024]. Hap3 infants spent less time than Hap1/2 infants in social contact [F(2,22)=13.11, P<0.001]. MPR/SPR/Hap3 infants exhibited more anxiety at 18 Mo. than Hap1/2 infants [F(3,22)=2.01, P=0.042]. MPR/CC infants fear-vocalized less at 6 and 18 Mo. than MPR/CG/GG infants, while PR infants demonstrated the reverse [F(2,22)=2.59, P=0.026]. These first findings in young monkeys have important implications for the roles of early life experience, serotonin expression and endorphin receptors in the development of stress responsivity and social behavior through adolescence.