Theta Oscillations Mediate Interaction between Prefrontal Cortex and Medial Temporal Lobe in Human Memory
Theta Oscillations Mediate Interaction between Prefrontal Cortex and Medial Temporal Lobe in Human Memory
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DOI：
10.1093/cercor/bhp223
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发表时间：
2010-07-01
期刊：
影响因子：
3.7
通讯作者：
Ding, Mingzhou
中科院分区：
文献类型：
--
作者：
Anderson, Kristopher L.;Rajagovindan, Rajasimhan;Ding, Mingzhou
众所周知，内侧颞叶（MTL）和前额皮质（PFC）是人类记忆过程的关键结构。此外，有人认为它们是记忆网络的一部分。尽管在血流动力学水平上观察到 PFC 和 MTL 之间的记忆调节相互作用，但仍不清楚介导这两个区域之间通信的神经元过程是什么。啮齿动物实验表明，theta 频段（4-8 Hz）的场振荡促进 PFC-MTL 相互作用。目前还没有在人体中报告过此类证据。为了解决这个问题，我们通过植入电极网格记录了 3 名执行言语自由回忆任务的癫痫患者的 MTL、PFC 和外侧颞叶的皮层电活动。使用参数谱方法对数据进行分析，以获得功效、相干性和格兰杰因果关系的估计。在自由回忆期间，与基线条件相比，PFC 和 MTL 之间的一致性值出现了任务调节的增加。同时，在回忆过程中，相干 PFC-MTL 位点对的数量显着增加。格兰杰因果关系分析进一步表明，一致性的增加是两个区域之间更高的双向信息流的结果，从 MTL 到 PFC 的驱动力通常更大，即 (MTL -> PFC) > (PFC -> MTL)。
The medial temporal lobe (MTL) and the prefrontal cortex (PFC) are known to be critical structures for human memory processes. Furthermore, it has been suggested that they are part of a memory network. Although memory-modulated interaction between PFC and MTL has been observed at the hemodynamic level, it remains unclear what the neuronal process is that mediates the communication between these 2 areas. Experiments in rodents suggest that field oscillations in the theta band (4-8 Hz) facilitate PFC-MTL interaction. No such evidence has been reported in humans. To address this problem, cortical electrical activity from MTL, PFC, and lateral temporal lobe was recorded from implanted electrode grids in 3 epilepsy patients performing a verbal free recall task. The data were analyzed using a parametric spectral method to obtain estimates of power, coherence, and Granger causality. A task-modulated increase in coherence values between PFC and MTL was seen during free recall as opposed to a baseline condition. Concurrently, the number of coherent PFC-MTL site pairs was significantly increased during recall. Granger causality analysis further revealed that the increased coherence is a consequence of higher bidirectional information flow between the 2 regions, with a generally greater driving from MTL to PFC, namely, (MTL -> PFC) > (PFC -> MTL).