Social recognition is fundamental for social decision making and the establishment of long-lasting affiliative behaviors in behaviorally complex social groups. It is a critical step in establishing a selective preference for a social partner or group member. C57BL/6J lab mice do not form monogamous relationships, and typically do not show prolonged social preferences for familiar mice. The CA2 hippocampal subfield plays a crucial role in social memory and optogenetic stimulation of inputs to the dorsal CA2 field during a short memory acquisition period can enhance and extend social memories in mice. Here, we show that partner preference in mice can be induced by chemogenetic selective stimulation of the monosynaptic projections from the hypothalamic paraventricular nucleus (PVN) to the CA2 during the cohabitation period. Specifically, male mice spend more time in social contact, grooming and huddling with the partner compared to a novel female. Preference was not induced by prolonging the cohabitation period and allowing more time for social interactions and males to sire pups with the familiar female. These results suggest that PVN-to-CA2 projections are part of an evolutionarily conserved neural circuitry underlying the formation of social preference and may promote behavioral changes with appropriate stimulation.

中文翻译：

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通过 CA2 海马亚区的化学遗传学刺激诱导小鼠的伴侣偏好。


社会认可是社会决策和在行为复杂的社会群体中建立持久的亲和行为的基础。这是建立对社会伙伴或团体成员的选择性偏好的关键一步。 C57BL/6J 实验室小鼠不形成一夫一妻制关系，通常不会对熟悉的小鼠表现出长期的社会偏好。 CA2 海马亚区在社会记忆中起着至关重要的作用，在短暂的记忆获取期间对背侧 CA2 区进行光遗传学刺激可以增强和延长小鼠的社会记忆。在这里，我们表明，在同居期间，化学遗传学选择性刺激从下丘脑室旁核（PVN）到 CA2 的单突触投射可以诱导小鼠的伴侣偏好。具体来说，与新的雌性小鼠相比，雄性小鼠花更多的时间进行社交接触、梳理毛发以及与伴侣挤在一起。延长同居期、留出更多时间进行社交活动以及雄性与熟悉的雌性生下幼崽并不会引发偏好。这些结果表明，PVN 到 CA2 的投射是形成社会偏好的进化保守神经回路的一部分，并且可能通过适当的刺激促进行为变化。