Zuckerman Mind Brain Behavior Institute, Columbia University, New York City, NY, USA.
National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
Nat Neurosci. 2024 Nov;27(11):2193-2206. doi: 10.1038/s41593-024-01771-8. Epub 2024 Oct 15.
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.
海马体背角 2（dCA2）区域能够区分新的和熟悉的同种个体。然而，更复杂的社会空间情景记忆的神经基础尚不清楚。本文报告称，不愉快社交经历的空间和社交内容需要不同的海马体区域。在不愉快的社交经历中，背侧 CA1（dCA1）锥体神经元介导了对不愉快地点的记忆，而 dCA2 锥体神经元则使雌雄小鼠能够区分威胁相关（CS）和安全相关（CS）的同种个体。在编码或回忆试验期间抑制 dCA2 会破坏社交恐惧的辨别记忆，导致对 CS 和 CS 小鼠均产生恐惧反应。钙成像显示，不愉快的经历增强并稳定了 dCA2 对 CS 和 CS 小鼠的表达，将社交价值的抽象表示纳入了社交身份的表示中。因此，dCA2 有助于在不愉快的社交情景记忆中检测社会新颖性，并对威胁相关个体与安全相关个体进行适应性辨别。
