Real-time Changes In Mononuclear Transmitters Of Nucleus Accumbens In Social Interactions And Regulation Of Oxytocin

Social behavior plays important role in survival and reproduction of human and social animals.Many mental diseases such as depression,anxiety,schizophrenia and Parkinson’s disease are accompanied by disorder in social behaviors.Treatments of most psychiatric diseases targeted monoamine system in the brain.Therefore,clarifying the changes in real-time release of monoamine neurotransmitters during different social interactions can not only reveal the neurophysiological mechanism underlying social behavior,but also provide some new idea for the treatment and prevention of mental illness.The nucleus accumbens is part of the ventral striatum,located in the anterior part of the anterior union,the ventral side of the striatum,the inside of the striatum,and the olfactory tube beneath the caudate shell.The nucleus accumbens is divided into two parts:the nucleus and the shell.The shell of the nucleus accumbens plays an important role in the emotional and motivational functions,and the nucleus of the nucleus accumbens involves the function of the body movement.The nucleus accumbens plays an important role in feeding,rewarding,stress and self-administration,and is a link between movement and mood and emotion,a gate or a filter that deals with emotional and emotional information.And the role of nucleus accumbens in motivations,behaviors,neuropsychiatric disorders and drug addiction is increasingly valued by biologists,and the monoamine neurotransmitters(norepinephrine,epinephrine,dopamine,serotonin)plays an important role in the regulation of mood and exercise.The previous studies in this brain area mainly focus on the role of a monoamine neurotransmitter in drug addiction and self-administration,and investigate the mechanism underlying seeking drug behavior and similar preferences such as partner-preference.Because of limitation in research techniques,the relationship between the four monoamine neurotransmitters and social interactions in the nucleus accumbens and how the releases of four monoamine neurotransmitters change in real time in during social interaction remains unclear.In addition,the nucleus accumbens is a key component of the midbrain border dopamine reward pathway and involves both the regulation of addiction and the effect of drug abuse.Recently there is evidence that injecting oxytocin to the nucleus accumbens can promote social interactions in the non-reproductive environment of the Mandarin voles.The oxytocin works by binding to the oxytocin receptors,and the oxytocin receptors are widely distributed in the nucleus accumbens.Oxytocin on the psychological and spiritual aspects of the regulatory role also shows a certain clinical application prospects,although the study found that a variety of social behavior can lead to the release of oxytocin,but whether oxytocin in the nucleus accumbens can cause changes in the release of monoamine neurotransmitters in order to regulate different social interactions is still unclear.Therefore,in the present study,the microdialysis technique was used to detect the real-time release of monoamine neurotransmitters such as norepinephrine,epinephrine,dopamine and serotonin in the nucleus accumbens of male Manarin voles during different social interaction.In addition,a dialysis dual probe was used to investigate the effect of OT microinjection on the release of monoamine neurotransmitters.The results are as follows:1.Changes in release levels of monoamine neurotransmitters in the nucleus accumbens in different social interaction:In the face of strange female and strange male voles,the norepinephrine release levels in male voles significantly increased;the norepinephrine release showed a trend to increase when they encountered familiar female voles.When the male voles interacted with the strange male and familiar male voles,their adrenaline release levels significantly decreased;the adrenaline displayed a trend to decrease when they encountered the strange female and familiar female voles.Dopamine release levels display an increased tendency when the male voles interact with the strange female and familiar female voles.Dopamine release levels decreased significantly while the male voles encountered the strange male and familiar male voles.During interaction with the strange female and strange male voles,the serotonin release increased significantly,while the serotonin release had an increasing trend when they encountered familiar female and familiar male voles.2.Correlation between specific behaviors and monoamine neurotransmitters release levels:During interaction with strange female voles,the level of serotonin release was positively correlated with levels of climbing behavior.There was a positive correlation between levels of norepinephrine release and investigating while interaction with unfamiliar voles;dopamine release level was positively correlated with levels of chasing.When the male voles interacted with familiar female,norepinephrine release level was negatively correlated with levels of investigating and was positively correlated with levels of aggression and staring;while serotonin release level was positively correlated with levels of aggressive behavior.When the male voles encountered with a familiar male,both levels of norepinephrine and adrenaline release were positively correlated with the levels of physical contact,investigating and chasing.Dopamine release level was positively correlated with the levels of investigating and serotonin release level was positively correlated with levels of submission behavior.Our experiment results show that:the changes in the release levels of monoamine neurotransmitters in the nucleus accumbens are closely related to the different behavior in social interaction,and different neurotransmitters play different role in different behaviors.3.Effects of oxytocin on monoamine neurotransmitter releaseThe level of norepinephrine release in the nucleus accumbens was significantly down-regulated by oxytocin,the levels of dopamine and serotonin release were up-regulated after oxytocin injection.This result indicates that the release level of monoamine neurotransmitters is regulated by oxytocin in nucleus accumbens.Considering the changes in levels of monoamine neurotransmitters release in different social interaction we speculate that:although the injection of oxytocin into nucleus accumbens may cause changes in levels of some monoamine neurotransmitters release,the levels of monoamine neurotransmitters release may be mediated by many other neuromodulators.In this study,the findings regarding the release of monoamine neurotransmitters in the social interaction,the relationship between monoamine neurotransmitters and social behavior,as well as the relationship between oxytocin and monoamine neurotransmitter release,provides an important basis for revealing neuroendocrine mechanisms of social behavior,as well as suggestions and new idea in the treatments for human psychiatric disorders.