Oxytocin, vasopressin and trust: Associations with aggressive behavior in healthy young males

Neuropeptides affecting social behavior in mammals: Oxytocin

Oxytocin (OXT), a neuropeptide consisting of only nine amino acids, is synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. Although OXT is best known for its role in lactation and parturition, recent research has shown that it also has a significant impact on social behaviors in mammals. However, a comprehensive review of this topic is still lacking. In this paper, we systematically reviewed the effects of OXT on social behavior in mammals. These effects of OXT from the perspective of five key behavioral dimensions were summarized: parental behavior, anxiety, aggression, attachment, and empathy. To date, researchers have agreed that OXT plays a positive regulatory role in a wide range of social behaviors, but there have been controversially reported results. In this review, we have provided a detailed panorama of the role of OXT in social behavior and, for the first time, delved into the underlying regulatory mechanisms, which may help better understand the multifaceted role of OXT. Levels of OXT in previous human studies were also summarized to provide insights for diagnosis of mental disorders.

The relationship between mistrust and aggression from childhood to adulthood

The study examined the relationship between mistrust and aggression from childhood to adulthood. The participants resided in Portugal and were tested during middle childhood (Mage = 7.5, SD = 0.81 years, n = 445, 240 male), preadolescence (Mage = 11.92, SD = 0.96 years, n = 431, 200 male), mid-adolescence (Mage = 14.70, SD = 0.91 years, n = 326, 201 male), late adolescence (Mage = 18.14, SD = 1.19 years, n = 410, 216 male), and adulthood (Mage = 26.56, SD = 1.13, years, n = 417, 197 male). Mothers reported the participants' mistrust during childhood and preadolescence on items from the Child Behavior Checklist. Aggression was assessed by standardized self-report measures at each age period. It was found that mistrust was associated with aggression during preadolescence and predicted changes in aggression to mid-adolescence and adulthood. The findings supported the conclusion that mistrust during preadolescence predisposes individuals to show aggression later in the life course.

Intranasal Oxytocin in Pediatric Populations: Exploring the Potential for Reducing Irritability and Modulating Neural Responses: A Mini Review

Endogenous neuropeptide Oxytocin (OXT) plays a crucial role in modulating pro-social behavior and the neural response to social/emotional stimuli. Intranasal administration is the most common method of delivering OXT. Intranasal OXT has been implemented in clinical studies of various psychiatric disorders with mixed results, mainly related to lack of solid pharmacodynamics and pharmacokinetics model. Due to intranasal OXT's mechanism of reducing the activation of neural areas implicated in emotional responding and emotion regulation, a psychopathology with this target mechanism could be potentially excellent candidate for future clinical trial. In this regard, irritability in youth may be a very promising target for clinical studies of intranasal OXT. Here we provide a mini-review of fifteen randomized controlled trials in pediatric patients with diagnoses of autism spectrum disorder (ASD), Prader-Willi syndrome (PWS), or Phelan-McDermid syndrome (PMS). Most studies had small sample sizes and varying dosages, with changes in irritability, mainly as adverse events (AEs). Neuroimaging results showed modulation of the reward processing system and the neural areas implicated in social-emotional information processing by intranasal OXT administration. Further research is needed to determine the most effective dose and duration of OXT treatment, carefully select target psychopathologies, verify target engagement, and measure adverse event profiles.

The relation between young adults' trust beliefs in others and interpersonal hostility

The research examined whether, and if so how, young adults' trust beliefs in others were associated with interpersonal hostility. The participants in Study 1 were 139 young adults from the UK (76 women; Mage = 20.8). In Study 2, 88 young adult women from the UK (Mage = 21.5) served as participants. The participants completed a standardized measure of trust beliefs in others (total with reliability, honesty, and emotional subscales). In Study 1, participants imagined they were victims of peer provocation. They were required to judge the intention for the provocation and their retaliation to it. In Study 2, the participants were engaged in a lab-based acquaintanceship interaction that involved the exchange of disclosures. They completed an adjective checklist that assessed anger and evaluated the quality of the conversation. Trust beliefs were linearly and negatively associated with the attribution of hostile intentions, retaliation, anger toward others, and critical evaluation of a developing peer relationship. As expected though, quadratic relations were found. Young adults with very low and those with very high trust beliefs (primarily emotionally based) showed greater attribution of hostile intentions, retaliation, anger toward others, and critical evaluation of a developing peer relationship than did young adults with the middle range of trust beliefs. The linear relations supported the hypothesis that trust promotes psychosocial adjustment. The quadratic relations supported the deviation from the normative trust (centralist) approach primarily for emotional trust beliefs in others.

Links Between the Neurobiology of Oxytocin and Human Musicality

The human species possesses two complementary, yet distinct, universal communication systems—language and music. Functional imaging studies have revealed that some core elements of these two systems are processed in closely related brain regions, but there are also clear differences in brain circuitry that likely underlie differences in functionality. Music affects many aspects of human behavior, especially in encouraging prosocial interactions and promoting trust and cooperation within groups of culturally compatible but not necessarily genetically related individuals. Music, presumably via its impact on the limbic system, is also rewarding and motivating, and music can facilitate aspects of learning and memory. In this review these special characteristics of music are considered in light of recent research on the neuroscience of the peptide oxytocin, a hormone that has both peripheral and central actions, that plays a role in many complex human behaviors, and whose expression has recently been reported to be affected by music-related activities. I will first briefly discuss what is currently known about the peptide’s physiological actions on neurons and its interactions with other neuromodulator systems, then summarize recent advances in our knowledge of the distribution of oxytocin and its receptor (OXTR) in the human brain. Next, the complex links between oxytocin and various social behaviors in humans are considered. First, how endogenous oxytocin levels relate to individual personality traits, and then how exogenous, intranasal application of oxytocin affects behaviors such as trust, empathy, reciprocity, group conformity, anxiety, and overall social decision making under different environmental conditions. It is argued that many of these characteristics of oxytocin biology closely mirror the diverse effects that music has on human cognition and emotion, providing a link to the important role music has played throughout human evolutionary history and helping to explain why music remains a special prosocial human asset. Finally, it is suggested that there is a potential synergy in combining oxytocin- and music-based strategies to improve general health and aid in the treatment of various neurological dysfunctions.

A Novel Role of CD38 and Oxytocin as Tandem Molecular Moderators of Human Social Behavior

Oxytocin is an important modulator of human affiliative behaviors, including social skills, human pair bonding, and friendship. CD38 will be discussed as an immune marker and then in more detail the mechanisms of CD38 on releasing brain oxytocin. Mention is made of the paralogue of oxytocin, vasopressin, that has often overlapping and complementary functions with oxytocin on social behavior. Curiously, vasopressin does not require CD38 to be released from the brain. This review discusses the social salience hypothesis of oxytocin action, a novel view of how this molecule influences much of human social behaviors often in contradictory ways. The oxytocinergic-vasopressinergic systems are crucial modulators of broad aspects of human personality. Of special interest are studies of these two hormones in trust related behavior observed using behavioral economic games. This review also covers the role of oxytocin in parenting and parental attachment. In conclusion, the effects of oxytocin on human behavior depend on the individual's social context and importantly as well, the individual's cultural milieu, viz. East and West. ACRONYMS: ACC = Anterior Cingulate ADP = Adenosine diphosphate AQ = Autism Quotient cADPR = Cyclic ADP-ribose CNS = Central nervous system DA = Dopamine eQTLC = Expression Quantitative Trait Loci LC-NE = Locus Coeruleus-Norepinephrine MRI = Magnetic Resonance Imaging OFC = Orbitofrontal cortices OXT = Oxytocin RAGE = Receptor for advanced glycation end-products SARM1 = Sterile Alpha and toll/interleukin-1 receptor motif-containing 1 TRPM2= Transient Receptor Potential Cation Channel Subfamily M Member 2 AVP = Vasopressin.