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重要神经生物学基础，在众多物种的社会行为中扮演着关键角色，诸如鱼类与鸟类，以及在社会性一夫一妻制的啮齿类动物间调节配偶间关系的作用已得到充分证实。绵猴展现出与社会性一夫一妻制相关的特征，包括高亲密度、双亲抚育、分离时的焦虑以及对外来者的攻击性；这些行为模式在其关系发展过程中亦有所变化。这种时间性的变化可能反映了不断变化的需求，因为成对个体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及其配对时长对社会行为在分离后重逢配偶时的作用。绵猴被从其家庭环境中移出，并接受针对D1和D2受体亚型的激动剂和拮抗剂治疗。它们被置于一个包含异性陌生人和配偶的新环境中，随后在家庭围栏中与配偶重逢。长期配对的绵猴在重逢时表现出比短期配对绵猴更高的食物共享水平，长期配对中的雌性比雄性共享食物的比例更高；在短期配对中未观察到性别差异。短期配对的个体在重逢时花费更多时间梳理配偶而非接受梳理，而长期配对的绵猴在梳理行为上表现出相似的数量，无论是主动梳理还是接受梳理。多巴胺治疗改变了配对层面的行为。当雌性接受D2激动剂或拮抗剂时，与雄性接受相同治疗相比，短期配对的绵猴在亲近时间上花费更少。在长期配对中，对雌性使用D1激动剂或拮抗剂治疗导致配对在社交亲近时间上比雄性治疗时更少。这些发现表明，多巴胺系统在配偶行为中的作用可能在啮齿类和灵长类动物中相似，其中D1系统调节长期配对中的行为表达，而D2系统则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具有深远进化根源的研究。