Arginine Vasopressin and Oxytocin Modulate Human Social Behavior
ABSTRACT Increasing evidence suggests that two nonapeptides, arginine vasopressin and oxytocin, shape human social behavior in both nonclinical and clinical subjects. Evidence is discussed that in autism spectrum disorders genetic polymorphisms in the vasopressin–oxytocin pathway, notably the arginine vasopressin receptor 1a (AVPR1a), the oxytocin receptor (OXTR), neurophysin I and II, and CD38 (recently shown to be critical for social behavior by mediating oxytocin secretion) contribute to deficits in socialization skills in this group of patients. We also present first evidence that CD38 expression in lymphoblastoid cells derived from subjects diagnosed with autism is correlated with social skill phenotype inventoried by the Vineland Adaptive Behavioral Scales. Additionally, we discuss molecular genetic evidence that in nonclinical subjects both AVPR1a and OXTR genes contribute to prosocial or altruistic behavior inventoried by two experimental paradigms, the dictator game and social values orientation. The role of the AVPR1a is also analyzed in prepulse inhibition. Prepulse inhibition of the startle response to auditory stimuli is a largely autonomic response that resonates with social cognition in both animal models and humans. First results are presented showing that intranasal administration of arginine vasopressin increases salivary cortisol levels in the Trier Social Stress test. To summarize, accumulating studies employing a broad array of cutting-edge tools in psychology, neuroeconomics, molecular genetics, pharmacology, electrophysiology, and brain imaging are beginning to elaborate the intriguing role of oxytocin and arginine vasopressin in human social behavior. We expect that future studies will continue this advance and deepen our understanding of these complex events.
- SourceAvailable from: Leonardo Emberti Gialloreti[Show abstract] [Hide abstract]
ABSTRACT: The etiology of Autism Spectrum Disorders (ASDs) continues to be elusive. While ASDs have been shown to be heritable, several environmental co-factors, such as, e.g. pre- or perinatal adverse events, could play a role in the pathogenesis of the disorder as well. Prevalence of ASDs appears to have increased in the last three decades, but the causes of this surge are not fully understood. As perinatal adverse events have increased as well, they have been regarded as logical contributors to the risen prevalence of ASDs. Over the last three decades there has been also a considerable increase in the rates of induced labor and caesarean sections (CS). However, even if a causal association between CS and ASDs increase has been suggested, it has not yet been proven. Nevertheless, we hypothesize here that such an association is actual and that it might help to explain a part of the increase in ASD diagnoses. Our assumption is based on the wider epidemiological picture of ASDs and CS, as well as on the possible biological plausibility of this correlation, by postulating potential epigenetic and neurobiological mechanisms underpinning this relationship. Today, several observations point toward the existence of epigenetic dysregulation in ASDs and this raises the issue of the role of environmental factors in bringing about epigenetic modifications. Epigenetic dysregulations in some brain neuropeptide systems could play a role in the behavioral dysfunctions of ASDs. Particularly, some evidence suggests a dysregulation of the oxytocinergic system in autistic brains. Perinatal alterations of oxytocin (OT) can also have life-long lasting effects on the development of social behaviors. Within the perinatal period, various processes, like pitocin infusion or CS, can alter the OT balance in the newborn; OT dysregulation could then interact with genetic factors, leading ultimately to the development of ASDs. Large long-term prospective studies are needed to identify causal pathways for ASDs and examine whether and how (epi-)genetic susceptibility interacts with obstetric risk factors in the development of ASDs. A better understanding of such a potential interplay could become paradigmatic for a wide range of genetic-environmental interactions in ASDs.Medical Hypotheses 03/2014; 82(6). DOI:10.1016/j.mehy.2014.03.011 · 1.15 Impact Factor
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ABSTRACT: Primates and other mammals show measurable, heritable variation in behav-ioral traits such as gregariousness, timidity, and aggression. Connections among be-havior, environment, neuroanatomy, and genetics are complex, but small genetic differences can have large effects on behavioral phenotypes. One of the best examples of a single gene with large effects on natural variation in social behavior is AVPR1A, which codes for a receptor of the peptide hormone arginine vasopressin. Work on rodents shows a likely causal association between AVPR1A regulatory polymorphisms and social behavior. Chimpanzees also show variation in the AVPR1A regulatory region, with some individuals lacking a ca. 350-bp segment corresponding to a putative functional element. Thus, chimpanzees have a "short" allele (segment deletion) and a "long" allele (no deletion) at this locus. Here we compare AVPR1A variation in two chimpanzee populations, and we examine behavioral and hormonal data in relation to AVPR1A genotypes. We genotyped AVPR1A in a captive population of western chimpanzees (Pan troglodytes verus, New Iberia Research Center; N = 64) for whichInternational Journal of Primatology 02/2014; 35(1). DOI:10.1007/s10764-013-9747-z · 1.99 Impact Factor
Chapter: Genetics of Human Social Behaviour[Show abstract] [Hide abstract]
ABSTRACT: Our species, Homo sapiens, displays the most multifaceted social behaviour ever to evolve, far exceeding all other social species from eusocial insects to our nearest primate relatives. This intricate social behaviour underpins our remarkable success in evolving from cooperation in small bands of hunter gatherers �100000 yearsagoto the apex of globalisation that characterises the twenty-first century political and economic institutions. Although our social brains are remarkably flexible, a significant part of our social behaviour is hardwired and embedded in our deoxyribonucleic acid (DNA) code. The human mind is not a tabula rasa, and our behaviour is constrained to a significant extent by our genes. That is not to say that environmentis unimportant; along with the genetic code, the interaction between environmentand genes makes us who we are. The overall role of genes and environment is revealed firstly by twin studies and then by leveraging the human genome project. The latter enables the identification of specific genes that, together with the environment, contribute to individual differences in human social behaviour.eLS, 11/2013: chapter Genetics of Human Social Behavior; John Wiley & Sons Ltd.