中国科学院脑科学与智能技术卓越创新中心徐春团队发现了背侧CA2到腹侧CA1回路有助于空间和情境依赖记忆。这一研究成果于2025年11月18日发表在国际顶尖学术期刊《神经科学通报》上。

课题组通过dCA2特异性电路追踪、单神经元投影组分析、光度Ca²⁺成像和光遗传学操作来研究dCA2神经元及其轴突投影在新物体识别、新位置识别和情境恐惧记忆行为范式中的生理作用。小组发现dCA2神经元将其最强的轴突投射发送到腹侧CA1 （vCA1d）的背侧，并显示出特定对象和位置的Ca²⁺反应。值得注意的是，dCA2-vCA1d投影有助于物体位置记忆的形成，而不是身份记忆的形成。

此外，光遗传学抑制dCA2-vCA1d轴突终端减少了对足部电击的恐惧反应和受损的情境记忆形成。总的来说，他们的研究揭示了dCA2-vCA1d回路在空间和上下文依赖记忆中的关键作用，为CA2神经元的功能提供了新的见解。

研究人员表示，海马背侧CA2亚区（dCA2）对社会记忆至关重要；然而，它对其他类型的海马体依赖性记忆的贡献尚未得到很好的理解。

附：英文原文

Title: The Dorsal CA2 to Ventral CA1 Circuit Contributes to Spatial and Context-Dependent Memories

Author: Li, Ning, Zhao, Bingqing, Shen, Xiaowen, He, Hua, Zhou, Jianxiang, Zhang, Jing, Xu, Lin, Chen, Xiaochun, Xu, Chun

Issue&Volume: 2025-11-18

Abstract: The hippocampal dorsal CA2 subregion (dCA2) is critical for social memory; however, its contribution to other types of hippocampus-dependent memories is not well understood. Here, we performed dCA2-specific circuit tracing, single-neuron projectome analysis, photometric Ca2+ imaging, and optogenetic manipulations to study the physiological roles of dCA2 neurons and their axon projections in behavioral paradigms for novel object recognition, novel location recognition, and contextual fear memory. We found that dCA2 neurons sent their strongest axon projections to the dorsal portion of ventral CA1 (vCA1d) and showed object and location-specific Ca2+ responses. Notably, the dCA2-vCA1d projection contributed to the memory formation of object location but not identity. Furthermore, optogenetic inhibition of the dCA2-vCA1d axon terminals reduced fear responses to foot shocks and impaired contextual memory formation. Collectively, our study reveals critical roles of the dCA2-vCA1d circuit in spatial and context-dependent memories, providing new insights into the function of CA2 neurons.

DOI: 10.1007/s12264-025-01535-9

Source: https://link.springer.com/article/10.1007/s12264-025-01535-9