Social reward is critical for social relationships, and yet we know little about the characteristics of social interactions that are rewarding or the neural mechanisms underlying that reward. Here, we investigate the sex-dependent role of oxytocin receptors within the ventral tegmental area (VTA) in mediating the magnitude and valence of social reward. Operant and classical conditioning tests were used to measure social reward associated with same-sex social interactions. The effects of oxytocin, selective oxytocin receptor agonists, antagonists, and vehicle injected into the VTA on social reward was determined in male and female Syrian hamsters. The colocalization of FOS and oxytocin in sites that project to the VTA following social interaction was also determined. Females find same-sex social interactions more rewarding than males and activation of oxytocin receptors in the VTA is critical for social reward in females, as well as males. These studies provide support for the hypothesis that there is an inverted U relationship between the duration of social interaction and social reward, mediated by oxytocin; and that in females the dose-response relationship is initiated at lower doses compared with males. Same-sex social interaction is more rewarding in females than in males, and an inverted U relationship mediated by oxytocin may have a critical role in assigning positive and negative valence to social stimuli. Understanding these sex differences in social reward processing may be essential for understanding the sex differences in the prevalence of many psychiatric disorders and the development of gender-specific treatments of neuropsychiatric disorders.

中文翻译：

---

腹侧被盖区中催产素受体对社会奖励的性别依赖性调节。

社会奖励对于社会关系至关重要，但我们对奖励的社会互动的特征或奖励所依据的神经机制知之甚少。在这里，我们调查了腹侧被盖区（VTA）中催产素受体的性别依赖性作用，以介导社会奖励的规模和效价。操作者和经典条件测试用于测量与同性社交互动相关的社交奖励。在雄性和雌性叙利亚仓鼠中确定了催产素，选择性催产素受体激动剂，拮抗剂和注入VTA的媒介物对社会奖励的影响。还确定了FOS和催产素在社交互动后投射到VTA的位点中的共定位。女性发现同性社交互动比男性更有意义，并且VTA中催产素受体的激活对于女性和男性的社交奖励都至关重要。这些研究为以下假设提供了支持：在催产素介导的社会互动持续时间和社会奖励之间存在倒置的U关系。与雌性相比，雌性的剂量-反应关系始于较低的剂量。与男性相比，女性的同性社交互动更有意义，由催产素介导的倒U型关系可能在为社会刺激分配正价和负价方面起关键作用。