Enhanced Theta and High-Gamma Coupling during Late Stage of Rule Switching Task in Rat Hippocampus
Enhanced Theta and High-Gamma Coupling during Late Stage of Rule Switching Task in Rat Hippocampus
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大鼠海马规则转换任务后期的增强 Theta 和高伽玛耦合
DOI：
10.1016/j.neuroscience.2019.05.053
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发表时间：
2019
期刊：
影响因子：
3.3
通讯作者：
Sakurai Yoshio
中科院分区：
文献类型：
--
作者：
Nakazono Tomoaki;Takahashi Susumu;Sakurai Yoshio
海马振荡，特别是theta（6-12 Hz）和gamma（30-90 Hz）频段，在几种认知功能中发挥重要作用。Theta和gamma振荡表现出交叉频率耦合（CFC），其中Theta节律的相位调节gamma振荡的幅度，这种CFC被认为反映了认知过程中的细胞组装动力学。先前的研究已经报道了CFC强度与学习过程相关。然而，这些动态相关性的细节尚未阐明。在本研究中，我们分析了大鼠海马在学习规则转换任务过程中记录的局部场电位。规则引导下的调制指数（CFC强度指标）高于无规则条件下的调制指数。在学习后期，theta和高gamma振荡（60-90 Hz）之间的耦合增强发生了变化。相比之下，theta和低gamma振荡（30-60 Hz）之间的耦合在学习过程中没有表现出任何变化。这些结果表明，在规则学习过程中存在theta和gamma波段之间的耦合，并且高和低gamma波段在规则转换中起不同的作用。
Hippocampal oscillations, particularly theta (6–12 Hz) and gamma (30–90 Hz) frequency bands, play an important role in several cognitive functions. Theta and gamma oscillations show cross-frequency coupling (CFC), wherein the phase of theta rhythm modulates the amplitude of the gamma oscillation, and this CFC is believed to reflect cell assembly dynamics in cognitive processes. Previous studies have reported that CFC strength correlates with the learning process. However, details on these dynamic correlations have not been elucidated. In the present study, we analyzed local field potentials recorded from the rat hippocampus during the learning of a rule-switching task. The modulation index, an index of the CFC strength, became higher in rule-guided behavior than in the no rule condition. The enhanced coupling between theta and high-gamma oscillations (60–90 Hz) changed during the late stage of learning. In contrast, the coupling between theta and low-gamma oscillations (30–60 Hz) did not show any changes during learning. These results suggest that the coupling between theta and gamma bands occurs during rule learning and that high- and low-gamma bands play different roles in rule switching.