Maintaining vs. enhancing motor sequence memories: Respective roles of striatal and hippocampal systems
Maintaining vs. enhancing motor sequence memories: Respective roles of striatal and hippocampal systems
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DOI：
10.1016/j.neuroimage.2014.12.049
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发表时间：
2015-03-01
期刊：
影响因子：
5.7
通讯作者：
Doyon, Julien
中科院分区：
文献类型：
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作者：
Albouy, Genevieve;Fogel, Stuart;Doyon, Julien
现在人们普遍认为，海马和纹状体依赖性记忆系统并不是独立运作的，而是在记忆获取和巩固过程中相互作用。然而，海马和纹状体在这些过程中各自的功能作用仍然未知。在这里，功能磁共振成像 (fMRI) 用于白天睡眠/觉醒方案来调查这一知识差距。使用我们实验室早期开发的协议（Albouy 等人，2013a），对显式顺序手指敲击任务的操作使我们能够分离序列的异向中心（空间）和自我中心（运动）表示，这分别由不同的海马皮质网络和纹状体皮质网络支持。重要的是，无论睡眠条件如何，海马依赖性记忆痕迹的睡眠依赖性性能增强，而纹状体依赖性记忆痕迹的性能得以维持。回归分析表明，这两个系统之间的交互影响了后续的性能改进。在异向中心表征中，纹状体活动与睡眠和清醒后的表现增强呈负相关，而在自我中心表征中，海马活动与表现改善呈正相关，但前提是训练后允许睡眠。我们的结果提供了巩固过程中功能分离的第一个直接证据，其中记忆稳定似乎由纹状体以时间依赖性方式支持，而记忆增强似乎与海马活动和睡眠依赖性过程有关。 (C) 2014 Elsevier Inc. 保留所有权利。
It is now accepted that hippocampal-and striatal-dependent memory systems do not act independently, but rather interact during both memory acquisition and consolidation. However, the respective functional roles of the hippocampus and the striatum in these processes remain unknown. Here, functional magnetic resonance imaging (fMRI) was used in a daytime sleep/wake protocol to investigate this knowledge gap. Using a protocol developed earlier in our lab (Albouy et al., 2013a), the manipulation of an explicit sequential finger-tapping task, allowed us to isolate allocentric (spatial) and egocentric (motor) representations of the sequence, which were supported by distinct hippocampo- and striato-cortical networks, respectively. Importantly, a sleep-dependent performance enhancement emerged for the hippocampal-dependent memory trace, whereas performance was maintained for the striatal-dependent memory trace, irrespective of the sleep condition. Regression analyses indicated that the interaction between these two systems influenced subsequent performance improvements. While striatal activity was negatively correlated with performance enhancement after both sleep and wakefulness in the allocentric representation, hippocampal activity was positively related to performance improvement for the egocentric representation, but only if sleep was allowed after training. Our results provide the first direct evidence of a functional dissociation in consolidation processes whereby memory stabilization seems supported by the striatum in a time-dependent manner whereas memory enhancement seems linked to hippocampal activity and sleep-dependent processes. (C) 2014 Elsevier Inc. All rights reserved.