Table_1_Dopamine Modulation of Reunion Behavior in Short and Long Term Marmoset Pairs.DOCX

One major neurobiological substrate regulating social processes is dopamine (DA). DA is implicated in social behavior in species as diverse as fish and birds, and has an established role in regulating relationships between mates in socially monogamous rodents. Marmoset monkeys display traits associated with social monogamy including high rates of affiliation, biparental care, distress upon separation, and aggression toward strangers; several of these behavioral patterns change throughout the development of relationships. This temporal change may represent changing demands, as pairs are likely to jointly face new experiences (e.g., parenthood) throughout pairing. We investigated the role of DA and pairing length on social behavior during reunion after separation from the mate. Marmosets were removed from their home environment and treated with agonists and antagonists for the D1 and D2 receptor subtypes. They were exposed to a novel environment containing an opposite-sex stranger and their pair mate, and then reunited with their mate in the home enclosure. Marmosets in long term pairs exhibited higher levels of food sharing during reunion than marmosets in short term pairs, with females in long term pairs sharing food more than males; no sex difference was observed in short term pairs. Subjects in short term pairs spent more time grooming their mate than receiving grooming during reunion, while marmosets in long term pairs displayed similar amounts of both initiated and received grooming. DA treatment altered pair-level behavior. When females received either a D2 agonist or antagonist, short term pairs spent less time in proximity, compared to when males received the same treatments. In long term pairs, treatment of females with either a D1 agonist or antagonist resulted in pairs spending less time in social proximity than when males were treated. These findings suggest that the function of the DA system in mate behavior may be similar between rodents and primates, with the D1 system modulating the expression of behavior in long term pairs and the D2 system regulating behavior in short term pairs. Furthermore, these results supplement a large body of work suggestive of deep evolutionary roots of the DA system in regulating social behavior.

多巴胺（DA）作为调节社会过程的主要神经生物学基础，其在调节鱼类和鸟类等物种的社会行为中扮演着重要角色，并在控制社会性一夫一妻鼠类之间的伴侣关系方面具有既定作用。卷尾猴表现出与社会性一夫一妻制相关的特征，包括高亲密度、双亲抚养、分离时的痛苦以及对外来者的攻击性；其中一些行为模式在关系发展的过程中会发生改变。这种时间上的变化可能代表着需求的转变，因为伴侣在配对过程中很可能会共同面对新的经历（例如，育儿）。本研究旨在探讨多巴胺和配对时长对分离后重逢期间社会行为的影响。卷尾猴被从其家庭环境中移除，并接受D1和D2受体亚型激动剂和拮抗剂的处理。它们被暴露于一个包含异性陌生人和其配对伴侣的新环境中，随后被带回家庭围栏与伴侣重逢。长期配对的卷尾猴在重逢时共享食物的水平高于短期配对的卷尾猴，长期配对中的雌性共享食物的比例高于雄性；在短期配对中未观察到性别差异。短期配对中的个体在重逢时花费更多时间梳理伴侣而非接受梳理，而长期配对的卷尾猴在主动梳理和接受梳理方面表现出的数量相似。多巴胺处理改变了配对层次的行为。当雌性接受D2激动剂或拮抗剂时，与雄性接受相同处理相比，短期配对的卷尾猴在接近时间上花费更少。在长期配对中，对雌性进行D1激动剂或拮抗剂的处理，导致配对在社会接近时间上比雄性接受处理时更少。这些发现表明，多巴胺系统在伴侣行为中的功能可能在啮齿动物和灵长类动物中相似，其中D1系统调节长期配对中行为的表达，而D2系统调节短期配对中的行为。此外，这些结果补充了大量关于多巴胺系统在调节社会行为中深层次进化根源的研究成果。