Social relationships among spouses, family members, and friends are known to affect physical and mental health. In particular, long-lasting bonds between socio-sexual partners have profound effects on cognitive, social, emotional, and physical well-being. We have previously reported that pair bonding in monogamous prairie voles (Microtus ochrogaster) is prevented by a single prolonged stress (SPS) paradigm, which causes behavioral and endocrine symptoms resembling post-traumatic stress disorder (PTSD) patients in rats (Arai et al., 2016). Since fear memory function is crucial for anxiety-related disorders such as PTSD, we investigated the effects of pair bonding on fear learning in prairie voles. We applied an SPS paradigm to male prairie voles after the cohabitation with a male (cage-mate group) or female (pair-bonded group). The cage-mate group, but not the pair-bonded group, showed enhanced fear response in a contextual fear conditioning test following the SPS treatment. Immunohistochemical analyses revealed that cFos-positive cells in the central amygdala were increased in the pair-bonded group after the contextual fear conditioning test and that oxytocin immunoreactivity in the paraventricular nucleus of the hypothalamus was significantly higher in the pair-bonded group than the cage-mate group. This pair-bonding dependent blunting of fear memory response was confirmed by a passive avoidance test, another fear-based learning test. Interestingly, intracerebroventricular injection of an oxytocin receptor antagonist 30 min before the passive avoidance test blocked the blunting effect of pair bonding on fear learning. Thus, pair bonding between socio-sexual partners results in social buffering in the absence of the partner, blunting fear learning, which may be mediated by oxytocin signaling.

中文翻译：

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催产素受体拮抗剂逆转了配对对一夫一妻制田鼠恐惧学习的钝化作用。

众所周知，配偶，家庭成员和朋友之间的社会关系会影响身心健康。尤其是，性伴侣之间的持久纽带对认知，社交，情感和身体健康有着深远的影响。我们以前曾报道过，单身长应力（SPS）范式阻止一夫一妻制田鼠（田鼠（Microtus ochrogaster））的成对键合，这会导致大鼠的行为和内分泌症状类似于创伤后应激障碍（PTSD）患者（Arai等人。 ，2016）。由于恐惧记忆功能对于与焦虑相关的疾病（如PTSD）至关重要，因此我们研究了成对键对草原田鼠恐惧学习的影响。在与雄性（笼伴侣组）或雌性（成对键组）同居后，我们对雄性大田鼠应用了SPS范例。笼友小组，SPS治疗后，通过情境恐惧调理测试显示对恐惧的反应增强，但对配对组却没有。免疫组织化学分析显示，经过情境恐惧条件测试后，成对键合组中杏仁核中央的cFos阳性细胞增加，并且成对键合组中下丘脑室旁核的催产素免疫反应性显着高于笼状伴侣组。恐惧记忆反应的这种成对依赖的钝化通过另一种基于恐惧的学习测试-被动回避测试得到了证实。有趣的是，在被动回避测试之前30分钟，脑室内注射催产素受体拮抗剂可阻断配对键对恐惧学习的钝化作用。从而，