Early experience in humans is associated with changes in neuropeptides critical for regulating social behavior

Abstract

The formation of social attachments is a critical component of human relationships. Infants begin to bond to their caregivers from the moment of birth, and these social bonds continue to provide regulatory emotional functions throughout adulthood. It is difficult to examine the interactions between social experience and the biological origins of these complex behaviors because children undergo both brain development and accumulate social experience at the same time. We had a rare opportunity to examine children who were reared in extremely aberrant social environments where they were deprived of the kind of care-giving typical for our species. The present experiment in nature provides insight into the role of early experience on the brain systems underlying the development of emotional behavior. These data indicate that the vasopressin and oxytocin neuropeptide systems, which are critical in the establishment of social bonds and the regulation of emotional behaviors, are affected by early social experience. The results of this experiment suggest a potential mechanism whose atypical function may explain the pervasive social and emotional difficulties observed in many children who have experienced aberrant care-giving. The present findings are consistent with the view that there is a critical role for early experience in the development of the brain systems underlying basic aspects of human social behavior.attachment ͉ emotion ͉ oxytocin ͉ vasopressin ͉ child abuse T he social attachments formed between human infants and their caregivers begin very early in postnatal life and play a critical role in children's survival and healthy adaptation. Typically, adults provide infants with a social environment that is fairly consistent. Caregivers learn how to recognize and respond to the infants' needs, thereby creating predictable contingencies in the environment; these regularities, in turn, make the infant's environment secure and conducive to further social learning (1, 2). Multiple perceptual, sensory, cognitive, and affective systems must become synchronized so that a social bond can develop between an infant and caregiver; this bond is then reflected in the child's adaptive behavioral responses to the environment. The goal of this experiment was to address a fundamental evolutionary and developmental question: To what extent are the neurobiological systems that regulate affiliative behaviors dependent on the social experiences afforded to most infants by their caregivers?It is difficult to evaluate the effects of early social experience on the organization of the developing brain because, within seconds of postnatal life, the human infant experiences a vast amount of emotional input. In this regard, the maturation of the brain is confounded with the accumulation of social experience. One way to address this problem is to experimentally manipulate the social environment. Although this approach is successful with nonhuman animals, such studies are neither possible nor desirable to undertake with human children. There...

Developmental Perspectives on Oxytocin and Vasopressin

“…Both men (Meinlschmidt and Heim, 2007) and women (Riem et al, 2013) show altered responses to intranasal oxytocin after a childhood with significant disruptions in the parent-child relationship. Further, peripheral (urine) oxytocin levels were lower after a social encounter in children with early life histories in institutional settings compared with children who were reared in typical home settings (Wismer Fries et al, 2005). These data in humans suggest that careful attention to experiences in childhood may help disentangle the true nature of the influence of oxytocin and vasopressin system genetics in developing and adult behavior.…”

Plasma Oxytocin and Arginine-Vasopressin Levels in Children with Autism Spectrum Disorder in China: Associations with Symptoms

“…A mutation may be inherited from parents or occur de novo. On the other hand, prenatal factors (like prenatal stressors [35] and drug abuse [36]) and the postnatal environment (like aberrant social environments [37]) may also lead to alteration of the OXT system, characterized by decreased central OXT mRNA levels and lower plasma OXT levels. Similar to OXT, studies on plasma AVP levels in ASD are limited and the results are controversial.…”

Invited Address: “The Times They Are A-Changin’” Gene Expression, Neuroplasticity, and Developmental Research

“…This suggests that that the oxytocin system may serve as a critical biological mechanism linking adversity to attachment style. Consistent with this idea, studies have linked childhood mistreatment to lower levels of oxytocin (Heim et al 2009;Wismer Fries et al 2005), and a recent study revealed that methylation (down regulation) of the oxytocin receptor gene mediates the effect of adult stress on changes in attachment style (Simons and Lei 2014). This pattern of results suggests that calibration of the oxytocin system serves to mediate the impact of childhood adversity J Youth Adolescence (2015) 44:573-580 577 on attachment style but that recalibration of this system can take place in adulthood.…”