Abstract # 2745 Poster # 48:

Scheduled for Sunday, September 20, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


BIOLOGICAL AND ADOPTIVE MOTHER-INFANT RELATIONSHIPS OF LABORATORY-REARED RHESUS MONKEYS (MACACA MULATTA) ACROSS THE FIRST SIX MONTHS OF LIFE: ADOPTIVE MOTHERS AND THEIR EFFECTS ON INFANTS' CORTISOL AND ACTH LEVELS

B. B. Jones1, B. Stringfellow1, W. Dennis1, T. Tate1, M. L. Schwandt2, S. G. Lindell2, C. S. Barr2, S. J. Suomi3 and J. D. Higley1
1Brigham Young University, Department of Neuroscience, Provo, UT 84602, USA, 2NIH Animal Center, NIAAA, LCTS, 3NIH Animal Center, NICHD, LCE
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Research evaluated genetic and environmental effects on plasma cortisol and ACTH levels in 567 rhesus monkey infants. Blood samples were obtained each month during the first 6 months of life to assay for cortisol and ACTH. Analyses showed interindividual stability across the first 6 months of life for both hormones in all monkeys regardless of rearing [average r>0.30], except for the peer-reared infants who showed little individual stability during the early months of life. To assess for genetic and environmental effects, adopted infants’ cortisol and ACTH levels were correlated with ACTH and cortisol from their unfamiliar biological and the adopted mothers who reared them [n=49]. Using multiple regression to control for sex differences, results showed that the infants’ average cortisol [r(48)=0.27, p=0.05] and ACTH [r(38)=0.42, p=0.009] levels were correlated with their adopted mothers for both cortisol and ACTH. For the biological mother, infant cortisol showed a trend toward being correlated [r(47)=0.25, p<0.1], but biological mothers’ ACTH was not correlated with her infants’ [r(27)=0.15, p=0.35]. ANOVAs showed that cortisol and ACTH were higher in the infants reared by their mothers than for infants reared with peers [F(3,331)=14.5, p=0.009]. Similar differences between the mother-reared and nursery-reared infants were shown for cortisol [F(3,294) =10.1, p<0.05], but in this case SPR infants had lower cortisol than PR infants [p=0.02]. These findings suggest that an infant’s HPA Axis response is influenced by the presence or absence of a mother and in mother’s treatment is a strong influence on the development of the HPA response.