Center for Behavioral Neuroscience, Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA.
Center for Behavioral Neuroscience, Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA.
Psychoneuroendocrinology. 2018 Sep;95:128-137. doi: 10.1016/j.psyneuen.2018.05.028. Epub 2018 May 21.
The rewarding properties of social interactions play a critical role in the development and maintenance of social relationships, and deficits in social reward are associated with various psychiatric disorders. In the present study, we used a novel Operant Social Preference (OSP) task to investigate the reinforcing properties of social interactions under conditions of high or low reward value, and high or low behavioral effort in male Syrian hamsters. Further, we investigated the role of oxytocin (OT) in a key structure of the mesolimbic reward system, the ventral tegmental area (VTA), in mediating the reinforcing properties of social interaction. Adult male hamsters were placed in a three-chambered apparatus, and allowed access to either a social chamber containing an unrestrained conspecific or a non-social chamber, by pushing through a one-way entry, vertical-swing door. Increasing the duration of social interaction (reward value) decreased the frequency of entering the social interaction chambers, whereas decreasing the duration of social interaction conversely increased the frequency of entries. Moreover, increasing behavioral effort required to access social interaction decreased the frequency of entries, especially under conditions when the duration of social interaction was only 5 s. OT injected into the VTA decreased the frequency of entering social interaction chambers in a manner similar to that observed when duration was increased, whereas injection of an OT receptor antagonist in the VTA increased the frequency of seeking social interaction. Taken together, these data support the hypothesis that activation of OT receptors in the VTA are critical for the reinforcing properties of social interactions. Furthermore, social interactions may exhibit duration and cost dependent reinforcing effects on behavior similar to those observed with food and drugs of abuse.
社交互动的奖励属性在社交关系的发展和维持中起着关键作用，而社交奖励的缺陷与各种精神障碍有关。在本研究中，我们使用一种新的操作性社交偏好（OSP）任务，在高或低奖励价值、高或低行为努力的条件下，研究社交互动的强化属性，在雄性叙利亚仓鼠中。此外，我们研究了催产素（OT）在中脑边缘奖励系统的关键结构腹侧被盖区（VTA）中的作用，以调节社交互动的强化属性。成年雄性仓鼠被放置在一个三室设备中，通过推开单向进入的垂直摆动门，允许进入一个包含不受限制的同种动物的社交室或一个非社交室。增加社交互动的持续时间（奖励价值）会降低进入社交互动室的频率，而减少社交互动的持续时间则会增加进入的频率。此外，增加进入社交互动所需的行为努力会降低进入的频率，尤其是在社交互动持续时间仅为 5 秒的情况下。OT 注入 VTA 以类似于增加持续时间时观察到的方式降低进入社交互动室的频率，而 VTA 中 OT 受体拮抗剂的注射增加了寻求社交互动的频率。总之，这些数据支持了这样的假设，即 VTA 中的 OT 受体的激活对于社交互动的强化属性是至关重要的。此外，社交互动可能表现出与食物和滥用药物类似的、依赖于持续时间和成本的强化作用。
