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Resilience and Vulnerability to Trauma 3512003; Liu et al., 2000). Meaney and colleagues also found that maternally separatedand nonhandled rat pups (in comparison to nonseparated, handled counterparts)displayed more hyperactive behavior in a novel setting, higher sensitivityto cocaine-induced locomotor activity, and greater increases in nucleus accumbensdopamine levels in the context of a mild stressor (tail-pinch; Brake et al., 2004).Coplan and Mathew’s studies (Coplan et al., 2005; Mathew et al., 2002) usingbonnet macaque monkeys have interesting implications for the impact of earlysocial environment on neurobiology. This set of studies, using a procedure called“variable foraging demand,” demonstrated that in nonhuman primates, developmentalstress can permanently alter the “set-point” of the HPA axis, thereforechanging the output of stress-related neurochemicals (reviewed by Gorman et al.,2002). Mothers were presented with a stressor: unpredictability of food availabilityfor 16 weeks within the first year of their offspring’s lives. Cerebrospinal fluid(CSF) samples were obtained simultaneously on mothers and infants. Both mothersand infants demonstrated elevated concentrations of CRF in their CSF, in comparisonto controls. Thus, early maternal stress without subsequent interventionpermanently altered the output of the HPA axis (i.e., increased CRF), producingneurobiological changes associated with increased vulnerability to stress (Coplanet al., 2005; Mathew et al., 2002).Similar findings are being reported in human children. A number of studies havedemonstrated that childhood abuse is associated with a cascade of neurobiologicalchanges that can alter the structure and function of the brain (reviewed byBremner, 2003; Heim & Nemeroff, 2002; Teicher et al., 2003). Structural findingsinclude decreased hippocampal volume (Vythilingam et al., 2002), smaller size ofthe corpus callosum, and abnormalities of the left neocortex and the amygdala (reviewedby Teicher et al., 2003). Abused children have also been found to havedecreased cerebral volume compared to nonabused children (reviewed by Heim& Nemeroff., 2002). Functional abnormalities include HPA-axis dysregulation(DeBellis et al., 1994), along with elevated cortisol levels (reviewed in Heim &Nemeroff, 2002) and increased electrical sensitivity of the limbic structures, whichgovern emotional processing. Abused children also have been found to exhibitpsychophysiological changes such as elevated heart rate, blood pressure changes,autonomic hyperactivity, and exaggerated startle response (reviewed in Heim &Nemeroff, 2002; Penza et al., 2003).The literature on abused children is supplemented by recent studies on thepsychoneuroendocrinology of Eastern European orphans. Research indicates thatlack of proper care and nurturance in childhood can create long-lasting changesin oxytocin and arginine vasopressin, hormones that regulate the formation andmaintenance of social bonds. Pollak’s recent study (Wismer Fries et al., 2005)found that Eastern European orphans had deficiencies in oxytocin, which confersa sense of protection, trust, and security (Heinrichs et al., 2003; Kosfeld et al.,2005), and in vasopressin, which facilitates recognition of familiar people and