Mouse OXT blocking peptide

Oxytocin (OXT) has previously been implicated in a range of prosocial behaviors such as trust and emotion recognition. Nevertheless, recent studies have questioned the evidence for this link. In addition, there has been relatively little conclusive research on the effect of OXT on empathic ability and such studies as there are have not examined the mechanisms through which OXT might affect empathy, or whether OXT selectively facilitates empathy for specific emotions. In the current study, we used eye-tracking to assess attention to socially relevant information while participants viewed dynamic, empathy-inducing video clips, in which protagonists expressed sadness, happiness, pain or fear. In a double-blind, within-subjects, randomized control trial, 40 healthy male participants received 24 IU intranasal OXT or placebo in two identical experimental sessions, separated by a 2 week interval. OXT led to an increase in time spent fixating upon the eye-region of the protagonist's face across emotions. OXT also selectively enhanced self-reported affective empathy for fear, but did not affect cognitive or affective empathy for other emotions. Nevertheless, there was no positive relationship between eye-gaze patterns and affective empathy, suggesting that although OXT influences eye-gaze and may enhance affective empathy for fear, these two systems are independent. Future studies need to further examine the effect of OXT on eye-gaze to fully ascertain whether this can explain the improvements in emotional behavior.

Oxytocin (OXT) is known to influence on social behaviors, including intermale aggression and hypothalamic pituitary -adrenal (HPA) axis activity. However, there are no data on the effects of oxytocin on intermale aggression and HPA axis activity in rats selected for elimination and enhancement of aggressiveness towards humans. The aim of this study is to elucidate the role of oxytocin in expression of aggressive behavior and stress response in Norway rats selected for elimination (tame) and enhancement (aggressive) of an aggressive-defensive reaction to humans. Oxytocin was administered to males via nasal applications once or for 5 days (daily). Resident-intruder test showed that in aggressive males, single oxytocin administration caused an increase in the latent period of aggressive interactions and a decrease in the percentage of direct aggression time (not including the time of lateral threat postures) as compared to the control aggressive rats administered with saline. After a 5 day oxytocin administration, aggressive animals demonstrated shorter time of aggressive interactions compared to the control rats. Resident-intruder test revealed no significant changes in behavior of tame rats after single oxytocin administration, while multiple administration caused an increase in aggressive behavior in tame rats. Oxytocin applications caused an elevation of corticosterone level after restriction in aggressive males, but did not affect expression of Crh, Crh1 and Crhr2 genes in hypothalamus in either tame or aggressive rats. The data obtained indicate significant role of oxytocinergic system in the behavior formed in the process of selection by reaction to humans.