The medial amygdala (MeA) plays a critical role in processing species- and sex-specific signals that trigger social and defensive behaviors. However, the principles by which this deep brain structure encodes social information is poorly understood. We used a miniature microscope to image the Ca²⁺ dynamics of large neural ensembles in awake behaving mice and tracked the responses of MeA neurons over several months. These recordings revealed spatially intermingled subsets of MeA neurons with distinct temporal dynamics. The encoding of social information in the MeA differed between males and females and relied on information from both individual cells and neuronal populations. By performing long-term Ca²⁺ imaging across different social contexts, we found that sexual experience triggers lasting and sex-specific changes in MeA activity, which, in males, involve signaling by oxytocin. These findings reveal basic principles underlying the brain's representation of social information and its modulation by intrinsic and extrinsic factors.

中文翻译：

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清醒行为小鼠内侧杏仁核中社会信息的神经元表征。

内侧杏仁核 (MeA) 在处理触发社会和防御行为的物种和性别特异性信号中起着关键作用。然而，人们对这种深层大脑结构编码社会信息的原理知之甚少。我们使用微型显微镜对清醒行为小鼠中大型神经群的 Ca ²⁺动力学进行成像，并在几个月内跟踪 MeA 神经元的反应。这些记录揭示了具有不同时间动态的 MeA 神经元空间混合子集。MeA 中社会信息的编码在男性和女性之间有所不同，并且依赖于来自单个细胞和神经元群体的信息。通过执行长期 Ca ²⁺通过跨不同社会背景的成像，我们发现性经历会触发 MeA 活动的持久和性别特异性变化，在男性中，这涉及催产素发出的信号。这些发现揭示了大脑对社会信息的表征及其受内在和外在因素的调节的基本原理。