Dopamine signaling mediates the formation of some types of social relationships, including reproductive pair bonds in the socially monogamous prairie vole (Microtus ochrogaster). In addition to these pair bonds with mates, prairie voles demonstrate selective preferences for familiar same-sex peers. The dependence of peer relationships on dopamine signaling has not been tested, and the mechanisms supporting these relationships may differ from those underlying pair bonds. We examined the effects of pharmacological manipulations of dopamine signaling on peer partner preference and socially conditioned place preference in female prairie voles. Haloperidol blockade of dopamine receptors at multiple doses did not alter selective preferences for familiar same-sex partners, suggesting that dopamine neurotransmission is not necessary for the formation of prairie vole peer relationships, unlike mate relationships. Dopamine receptor agonist apomorphine facilitated peer partner preferences under conditions normally insufficient for partner preference formation; however, in the absence of effects from blockade, it is difficult to distinguish between a role for dopamine in partner preference formation and the generally rewarding properties of a dopamine agonist. Prairie voles exhibited socially conditioned place preferences for new but not long-term same-sex peers, and these preferences were not blocked by haloperidol. These results suggest that prairie vole peer relationships are less dependent on dopamine signaling than pair bonds, while still being rewarding. The data support distinct roles of dopamine and motivation in prairie vole peer relationships relative to mate relationships, suggesting that reproductive bonds are mediated differently from non-reproductive ones.

多巴胺信号介导某些类型社会关系的形成，包括社会一夫一妻制的草原田鼠（Microtus ochrogaster）。除了与配偶的这些配对关系之外，草原田鼠还表现出对熟悉的同性同伴的选择性偏好。对等关系对多巴胺信号的依赖尚未经过测试，支持这些关系的机制可能与那些潜在的对键不同。我们研究了多巴胺信号的药理学操作对雌性草原田鼠的同伴伴侣偏好和社会条件位置偏好的影响。多剂量氟哌啶醇阻断多巴胺受体并没有改变熟悉的同性伴侣的选择性偏好，这表明与配偶关系不同，多巴胺神经传递对于形成草原田鼠同伴关系不是必需的。多巴胺受体激动剂阿扑吗啡在通常不足以形成伴侣偏好的条件下促进同伴偏好；然而，在没有阻断作用的情况下，很难区分多巴胺在伴侣偏好形成中的作用和多巴胺激动剂的一般奖励特性。草原田鼠对新的但不是长期的同性同龄人表现出社会条件下的位置偏好，而这些偏好并没有被氟哌啶醇阻止。这些结果表明，与配对债券相比，草原田鼠同伴关系对多巴胺信号的依赖程度较低，同时仍然是有益的。数据支持多巴胺和动机在相对于配偶关系的草原田鼠同伴关系中的不同作用，