The Hippocampus and Neocortical Inhibitory Engrams Protect against Memory Interference
The Hippocampus and Neocortical Inhibitory Engrams Protect against Memory Interference
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DOI：
10.1016/j.neuron.2018.11.042
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发表时间：
2019-02-06
期刊：
影响因子：
16.2
通讯作者：
Barron, Helen C.
中科院分区：
文献类型：
--
作者：
Koolschijn, Renee S.;Emir, Uzay E.;Barron, Helen C.
我们的经历经常相互重叠，但我们能够选择性地回忆个人记忆来指导决策和未来的行动。支持这种精确记忆回忆的神经机制仍不清楚。在这里，使用超高场7T MRI，我们揭示了保护记忆免受干扰的两种不同机制。第一种机制涉及海马体，其中血氧水平依赖（BOLD）信号预测记忆干扰的行为测量，并且根据其关系重叠将上下文依赖性记忆的表示模式分离。第二种机制涉及新皮层抑制。当我们使用经颅直流电刺激（tDCS）降低新皮层GABA的浓度时，新皮层记忆干扰与GABA的减少成比例增加，这反过来又预测了行为表现。这些研究结果表明，记忆干扰是由海马和新皮层介导的，海马使用关系信息将重叠但依赖于上下文的记忆分开，新皮层抑制防止重叠记忆之间不必要的共激活。
Our experiences often overlap with each other, yet we are able to selectively recall individual memories to guide decisions and future actions. The neural mechanisms that support such precise memory recall remain unclear. Here, using ultra-high field 7T MRI we reveal two distinct mechanisms that protect memories from interference. The first mechanism involves the hippocampus, where the blood-oxygen-level-dependent (BOLD) signal predicts behavioral measures of memory interference, and representations of context-dependent memories are pattern separated according to their relational overlap. The second mechanism involves neocortical inhibition. When we reduce the concentration of neocortical GABA using trans-cranial direct current stimulation (tDCS), neocortical memory interference increases in proportion to the reduction in GABA, which in turn predicts behavioral performance. These findings suggest that memory interference is mediated by both the hippocampus and neocortex, where the hippocampus separates overlapping but context-dependent memories using relational information, and neocortical inhibition prevents unwanted co-activation between overlapping memories.