Hippocampal ensemble dynamics timestamp events in long-term memory
Hippocampal ensemble dynamics timestamp events in long-term memory
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DOI：
10.7554/elife.12247
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发表时间：
2015-12-18
期刊：
影响因子：
7.7
通讯作者：
Ziv, Yaniv
中科院分区：
文献类型：
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作者：
Rubin, Alon;Geva, Nitzan;Ziv, Yaniv
记住不同事件之间时间关系的能力对于情景记忆至关重要，但目前对其潜在机制知之甚少。我们对小鼠海马CA1区的数千个神经元进行了为期数周的延时成像，因为它们反复访问了两个不同的环境。纵向分析暴露了正在进行的独立于环境的演化的情节表示，尽管稳定的地方字段的位置和两个环境之间的不断重新映射。这些动力学通过具有特定时间点特有的细胞组成和活动模式的神经元集合来标记经历的事件。时间上接近的事件共享一个共同的时间戳，而不管它们发生的空间背景如何。时间上遥远的事件具有不同的时间戳，即使它们发生在相同的空间背景下。我们的研究结果表明，天尺度的海马集成动力学可以支持一个心理时间轴的形成，其中经历的事件可以记忆相关或解离的时间距离的基础上。
The capacity to remember temporal relationships between different events is essential to episodic memory, but little is currently known about its underlying mechanisms. We performed time-lapse imaging of thousands of neurons over weeks in the hippocampal CA1 of mice as they repeatedly visited two distinct environments. Longitudinal analysis exposed ongoing environment-independent evolution of episodic representations, despite stable place field locations and constant remapping between the two environments. These dynamics time-stamped experienced events via neuronal ensembles that had cellular composition and activity patterns unique to specific points in time. Temporally close episodes shared a common timestamp regardless of the spatial context in which they occurred. Temporally remote episodes had distinct timestamps, even if they occurred within the same spatial context. Our results suggest that days-scale hippocampal ensemble dynamics could support the formation of a mental timeline in which experienced events could be mnemonically associated or dissociated based on their temporal distance.