Abstract # 1063 Poster # 166:

Scheduled for Friday, August 19, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation


SEROTONIN TRANSPORTER GENOTYPE AND EARLY ENVIRONMENTAL FACTORS CONTRIBUTE TO INFANT RHESUS MACAQUE BEHAVIORAL RESPONSE TO NOVELTY, HUMAN INTRUDER, AND MATERNAL SEPARATION

E. L. Kinnally1,2, G. M. Karere2,3, S. P. Mendoza1,2, W. A. Mason1,2, L. A. Lyons3 and J. P. Capitanio1,2
1Department of Psychology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA, 2California National Primate Research Center, 3Population Health and Reproduction, Veterinary Medical School, University of California at Davis
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     The developmental contributions of experience and genetics to individual differences in emotional regulation consist of dynamic interactions between molecular, neural, physiological and behavioral systems over time. It has been suggested that the serotonergic system is particularly sensitive to early experience, and may impact development of emotional reactivity. We assessed 369 3-4 month-old infant rhesus macaques by examining their contact with novel objects, responses to a human intruder, and behavior in a novel cage following maternal separation. Individuals were genotyped for a well-characterized functional polymorphism in the promoter region of the serotonin transporter gene (rh5-HTTLPR), and the contributions of environmental factors (such as social group composition) and genotype were examined. Individuals homozygous for the short allele (s/s) of the serotonin transporter promoter were consistently more emotionally reactive than other individuals (t-tests, P < 0.05). The effect of genotype was subject to environmental modulation, however, as long/short (l/s) heterozygous individuals who were nursery reared exhibited enhanced activity (t-tests, P < 0.05) and emotional reactivity (t-tests, P < 0.05) in response to maternal separation and a human intruder compared with individuals reared in social groups. These data suggest that emotional reactivity is influenced by both genotype and early experience in infant rhesus macaques.