Memory retrieval depends on reactivation of memory engram cells. Inadvertent activation of these cells is expected to cause memory-retrieval failure, but little is known about how noisy activity of memory-irrelevant neurons impacts mnemonic processes. Here, we report that optogenetic nonselective activation of only tens of hippocampal CA1 cells (∼0.01% of the total cells in the CA1 pyramidal cell layer) impairs contextual fear memory recall. Memory recall failure was associated with altered neuronal reactivation in the basolateral amygdala. These results indicate that hippocampal memory retrieval requires strictly regulated activation of a specific neuron ensemble and is easily disrupted by the introduction of noisy CA1 activity, suggesting that reactivating memory engram cells as well as silencing memory-irrelevant neurons are both crucial for memory retrieval.

中文翻译：

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情境恐惧记忆检索易受海马噪声的影响。

记忆检索依赖于记忆印迹细胞的重新激活。预计这些细胞的无意激活会导致记忆检索失败，但对于与记忆无关的神经元的嘈杂活动如何影响记忆过程知之甚少。在这里，我们报告仅数十个海马 CA1 细胞（占 CA1 锥体细胞层总细胞的 0.01%）的光遗传学非选择性激活会损害情境恐惧记忆回忆。记忆回忆失败与基底外侧杏仁核中神经元重新激活的改变有关。这些结果表明，海马记忆恢复需要严格调节特定神经元集合的激活，并且很容易被噪声 CA1 活动的引入所破坏，