Abstract # 2729 Poster # 56:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


DIFFERENT DEVELOPMENTAL OUTCOMES FOLLOWING LABORATORY REARING BY BIOLOGICAL OR ADOPTIVE MOTHERS: MATERNAL INFLUENCE ON BEHAVIORAL AND PHYSIOLOGICAL RESPONSES TO SEPARATION STRESS IN RHESUS MACAQUES (MACACA MULATTA)

A. N. Sorenson1,4, W. F. Maxwell1,4, M. L. Schwandt2, C. S. Barr2,3, S. J. Suomi3 and J. Higley1
1Brigham Young University, Department of Psychology, Provo, Utah, USA, 2NIH Animal Center, NIAAA, LCTS, Poolesville, MD 20837, 3NIH Animal Center, NICHD, LCE, 4first and second authors should be considered equal in order
line
     

Previous studies showed that over the first six months of life, during their day-to-day interactions, rhesus macaque infants reared by their biological mother show less anxiety and aggression than infants reared by an adoptive mother. This study compared infants reared by their biological mother (BM) with those reared by an unrelated adoptive mother (AM), during the stress of four repeated, 4-day social separations. Behavioral observations were obtained from 195 infants [154 BM, 41 AM] and physiological samples taken during the first and second hour and again on the final day of each separation. Analyses used mixed design repeated measures ANOVA, with rearing and week of separation as the independent variables. While the AM infants exhibited more environmental exploration on day 1 of the separation [F(1,141)=6.73, p<0.01], the BM infants demonstrated more agitation as exhibited by high stereotypic behavior across the entire separation period [F(1,160)=3.44, p<0.07 for day 1, and F(1,163)=5.37, p<0.03 for days 2-4], and more locomotion on days 2-4 [F(1,148)=4.11, p<0.045]. ACTH levels were higher in the AM infants over all separations [p<0.04]. Given previous studies, and these results, we posit that because AM infants are rejected by their adopted mother and left to interact with other group members, independent of their mother, they may develop more adult-like coping behaviors. However, lacking easy access to maternal contact, they exhibit elevated neuroendocrine stress responses.