The Role Of Oxytocin In Animal Prosocial Behavior And Its Research Progress

The Brandt's voles is a kind of social species,live in large family groups and show high levels of prosocial behavior among individuals in population of Brandt's voles.The greater long-tailed hamsters is a kind of solitary rodents,they live separately and showd high levels of aggression towards conspecifics and only the mother hamster take care of the infants.There were great differencesin the social behaviors between these two kinds of rodents.So we aim at comparing the differences in the expression level of oxytocin(OT)and oxytocin receptor(OTR)in the specific region of the Brandt's voles and the greater long-tailed hamsters.At the same time,we blocked oxytocin receptor in some brain regions of Brandt's voles,while injected OT in the brain region of the greater long-tailed hamsters.The results showed that the oxytocin blocked in nucleus accumbens can increase the aggressive behavior of Brandt's voles.While,injection of OT in nucleus accumbens of great long tailed hamsters can significantly reduced the aggressive behaviors of them.So we can draw the conclusion:OT can regulate animal social behavior,and the nucleus accumbens is the main region to affect prosocial behavior.We speculate that oxytocin is the main genetic regulating factors.4-month-old male Brandt's vole and male greater long-tailed hamsters were used in this study.The specific brain regionwere deducted according to the brain pattern of rat using frozen serial sections technology and Micro Punch needle.The Western Blotting was used to explore the difference of oxytocin and oxytocin receptor expression in the medial amygdala and nucleus accumbens between male Brandt's vole and male greater long-tailed hamsters.Previous studied had reported that MeA and NAcc were the main region to affected the social behavior of rodents.The results showed that there was a significant difference in the expression of oxytocin and oxytocin receptor between Brandt's vole and greater long-tailed hamsters.Four-month-old male Brandt's voles were selected to inject oxytocin receptor antagonists into the medial amygdala and nucleus accumbens respectively.We investigated the effects of oxytocin on the social behavior of Brandt's vole in the medial amygdala and the nucleus accumbens by social recognition experiment and neutral arena encounter experiment.The results showed that OT in the MeA had an effect on the social memory ability of Brandt's vole,resulting in its social recognition disorder,but had no effect on its social preference and aggressive behavior.We proposed that the oxytocin receptor antagonists injected into MeA of Brandt's vole could destroy Brandt's voles' social memory,rather than change it's prosociality.While,OT injected into the NAcc of Brandt's vole can defected their social memory;thire social preference and their aggressive behavior.Four-month-old male greater long-tailed hamsters were selected to inject oxytocin agonist into the nucleus accumbens.In order to increase the distribution of oxytocin in the NAcc brain area of greater long-tailed hamsters.To investigate the effect of oxytocin on the social behavior of greater long-tailed hamsters through social recognition experiment and the neutral area encounter experiment.The results showed that OT had a significant effect on the social inquiry behavior and aggressive behavior in NAcc of the greater long-tailed hamsters.