The Oxytocin–Vasopressin Pathway in the Context of Love and Fear

Abstract

Vasopressin (VP) and oxytocin (OT) are distinct molecules; these peptides and their receptors [OT receptor (OTR) and V1a receptor (V1aR)] also are evolved components of an integrated and adaptive system, here described as the OT–VP pathway. The more ancient peptide, VP, and the V1aRs support individual survival and play a role in defensive behaviors, including mobilization and aggression. OT and OTRs have been associated with positive social behaviors and may function as a biological metaphor for social attachment or “love.” However, complex behavioral functions, including selective sexual behaviors, social bonds, and parenting require combined activities of OT and VP. The behavioral effects of OT and VP vary depending on perceived emotional context and the history of the individual. Paradoxical or contextual actions of OT also may reflect differential interactions with the OTR and V1aR. Adding to the complexity of this pathway is the fact that OT and VP receptors are variable, across species, individuals, and brain region, and these receptors are capable of being epigenetically tuned. This variation may help to explain experience-related individual and sex differences in behaviors that are regulated by these peptides, including the capacity to form social attachments and the emotional consequences of these attachments.

Challenges for measuring oxytocin: The blind men and the elephant?

“…Lastly, although beyond the scope of the present paper, to fully understand the significance of peripheral measures of oxytocin it is important to recognize that oxytocin is a component of a phylogenetically ancient system that also includes vasopressin (Carter, 2017).…”

Role of oxytocin in the control of stress and food intake

“…241 Studies on the role of oxytocin in reproduction-related behaviours, including pair bonding, 206,242 mating and maternal behaviour of laboratory animals, 243 as well as in human behaviours requiring higher cognitive functions, including trust and altruism, have led to the prosocial hypothesis that oxytocin facilitates prosocial behaviours in general. Several hypotheses have been proposed to explain the actions of oxytocin in an integrative way.…”

“…Several hypotheses have been proposed to explain the actions of oxytocin in an integrative way. 241 Studies on the role of oxytocin in reproduction-related behaviours, including pair bonding, 206,242 mating and maternal behaviour of laboratory animals, 243 as well as in human behaviours requiring higher cognitive functions, including trust and altruism, have led to the prosocial hypothesis that oxytocin facilitates prosocial behaviours in general. 244 Oxytocin paired with charitable social cues has been shown in humans to reduce out-group rejection even in xenophobic individuals, although the effects of oxytocin appear to be dependent on the experimental conditions.…”

A monoclonal antibody raised against a synthetic oxytocin peptide stains mouse hypothalamic neurones

“…Using 7a5, we will be able to examine c‐Fos expression in 7a5‐positive oxytocin neurones after social stress . Social stress induces many cellular responses and an increased excitation of oxytocin neurones in the hypothalamus may be the first step for behavioural responses, such as adaptation and damping of stress. Such experiments are underway aiming to detect oxytocin neurones with 7a5 in mice exposed to stress.…”

“…Detection of oxytocin and oxytocinergic neurones in the brain is important for determining the functional role of oxytocin in social memory and behaviour in rodents and humans, including in subjects with psychiatric diseases such as autism spectrum disorder . There are several polyclonal and monoclonal antibodies that are used in such experiments .…”