Serotonin transporter gene variation, infant abuse, and responsiveness to stress in rhesus macaque mothers and infants

• Type of Material: Article
• Authors: Kai McCormack, Emory University; T. K. Newman, University of Cape Town; J. D. Higley, Brigham Young University; D. Maestripieri, Emory University; Maria Sanchez, Emory University
• Language: English
• Date: 2009-04-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: Copyright © 2019 Elsevier B.V. or its licensors or contributors.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.yhbeh.2009.01.009
• Title of Journal or Parent Work: Hormones and Behavior
• ISSN: 0018-506X
• Volume: 55
• Issue: 4
• Start Page: 538
• End Page: 547
• Grant/Funding Information: This work was supported by NIH grants MH065046 and MH58922 (MMS), MH62577 and MH63097 (DM), MD000215 (KM); and RR-00165 to the Yerkes National Primate Research Center; as well as by a FIRST fellowship (NIH K-12 grant GM00680 to KM); a NARSAD Young Investigator Award (MMS); and NIAAA Intramural funds.
• Keywords: INTERGENERATIONAL TRANSMISSION; PITUITARY-ADRENAL AXIS; PROMOTER POLYMORPHISM; HPA AXIS; REARING CONDITION; ANXIETY-RELATED TRAITS; Life Sciences & Biomedicine; Early experience; Maternal behavior; Science & Technology; EARLY EXPERIENCE; Genetic effects; Macaca mulatta; Developmental psychopathology; MONKEYS MACACA-MULATTA; Child maltreatment; Stress reactivity; 5-HTTLPR; FUNCTIONAL POLYMORPHISM; Endocrinology & Metabolism; rh5-HTTLPR; Serotonin transporter; Behavioral Sciences; MALTREATED CHILDREN
• Research Categories: Psychology, Behavioral; Biology, Zoology; Biology, Genetics

Abstract

A functional polymorphism in the promoter region of the serotonin transporter (5-HTTLPR) gene has been associated with variation in anxiety and hypothalamus-pituitary-adrenal (HPA) axis function in humans and rhesus macaques. Individuals carrying the short allele are at a higher risk for developmental psychopathology, and this risk is magnified in short allele carriers who have experienced early life stress. This study investigated the relationship between 5-HTTLPR allelic variation, infant abuse, and behavioral and hormonal responses to stress in rhesus macaques. Subjects were 10 abusive mothers and their infants, and 10 nonabusive mother-infant pairs. Mothers and infants were genotyped for the rh5-HTTLPR, and studied in the first 6 months of infant life. For mothers and infants, we measured social group behavior, behavioral responses to handling procedures, and plasma concentrations of ACTH and cortisol under basal conditions and in response to stress tests. The proportion of individuals carrying the short rh5-HTTLPR allele was significantly higher among abusive mothers than controls. Among mothers and infants, the short allele was associated with higher basal cortisol levels and greater hormonal stress responses in the infants. In addition, infants who carried the short rh5-HTTLPR allele had higher anxiety scores than infants homozygous for the long allele. The rh5-HTTLPR genotype also interacted with early adverse experience to impact HPA axis function in the infants. These results are consistent with those of previous studies which demonstrate associations between serotonergic activity and anxiety and stress reactivity, and add additional evidence suggesting that genetic variation in serotonergic function may contribute to the occurrence of abusive parenting in rhesus macaques and modulate emotional behavior and HPA axis function.