美国哥伦比亚大学Pegah Kassraian团队的最新研究发现，海马体ammonis 角2（CA2）区是区分社交安全和威胁的区域。相关论文于2024年10月15日发表于国际学术期刊《自然-神经科学》杂志。

据了解，海马背侧dCA2区域能够辨别新出现和熟悉的同种动物。然而，与更复杂社会空间记忆有关的神经基础尚不清楚。

研究人员发现厌恶性社交体验的空间和社交内容需要不同的海马区。在雌性和雄性小鼠中，背侧CA1（dCA1）锥体神经元介导了对厌恶位置的记忆，而dCA2锥体神经元则能区分与威胁（CS⁺）和与安全相关（CS^-）的同种异体。

在编码或回忆试验中沉默dCA2会破坏社会恐惧辨别记忆，导致对CS⁺和CS^-小鼠都产生恐惧反应。钙成像显示，厌恶体验加强并稳定了CS⁺和CS^-小鼠的dCA2表征，将社会价值的抽象表征纳入了社会身份表征。因此，在厌恶性社会偶发经历中，dCA2既有助于社会新奇感的检测，也有助于适应性地区分与威胁相关和安全相关的个体。

附：英文原文

Title: The hippocampal CA2 region discriminates social threat from social safety

Author: Kassraian, Pegah, Bigler, Shivani K., Gilly Suarez, Diana M., Shrotri, Neilesh, Barnett, Anastasia, Lee, Heon-Jin, Young, W. Scott, Siegelbaum, Steven A.

Issue&Volume: 2024-10-15

Abstract: The dorsal cornu ammonis 2 (dCA2) region of the hippocampus enables the discrimination of novel from familiar conspecifics. However, the neural bases for more complex social–spatial episodic memories are unknown. Here we report that the spatial and social contents of an aversive social experience require distinct hippocampal regions. While dorsal CA1 (dCA1) pyramidal neurons mediate the memory of an aversive location, dCA2 pyramidal neurons enable the discrimination of threat-associated (CS+) from safety-associated (CS) conspecifics in both female and male mice. Silencing dCA2 during encoding or recall trials disrupted social fear discrimination memory, resulting in fear responses toward both the CS+ and CS mice. Calcium imaging revealed that the aversive experience strengthened and stabilized dCA2 representations of both the CS+ and CS mice, with the incorporation of an abstract representation of social valence into representations of social identity. Thus, dCA2 contributes to both social novelty detection and the adaptive discrimination of threat-associated from safety-associated individuals during an aversive social episodic experience.

DOI: 10.1038/s41593-024-01771-8

Source: https://www.nature.com/articles/s41593-024-01771-8