Sjøgård Martin, Mylonas Dimitrios, Baxter Bryan, Shi Zhaoyue, Khan Sheraz, Demanuele Charmaine, Zhu Lin, Tocci Catherine, Stickgold Robert, Hämäläinen Matti S, Manoach Dara S
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02215.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129.
J Neurosci. 2025 Aug 20;45(34):e0381252025. doi: 10.1523/JNEUROSCI.0381-25.2025.
Sleep spindles play a critical role in sleep-dependent memory consolidation. Although spindles can occur widely across the cortex, they are often focal. Focal spindles may promote plasticity in distinct circuits to consolidate specific memory types. In this study, we simultaneously acquired EEG and magnetoencephalography (MEG) data from 25 healthy adults (six females) during daytime naps to investigate whether learning the finger tapping motor sequence task (MST) preferentially increases spindle density (#/min) within cortical regions engaged during task performance and whether these task-related spindle increases predict performance improvement measured after the nap. We employed a novel algorithm to project EEG/MEG signals into source space using anatomical constraints from MRI and detected spindles in cortical regions. Compared with a baseline nap, MST training preferentially increased spindle density in regions engaged while learning, which in turn predicted postnap performance improvement. Learning during training and postnap improvement were not correlated, suggesting that they reflect discrete processes. They also had different neural correlates. Whereas learning during training correlated with spindle density increases in motor execution regions, postnap improvement correlated with increases in motor planning regions. We speculate that spindles in motor execution regions represent the memory, while those in planning regions enhance future performance. Our findings demonstrate that spindle expression is influenced by prior learning and support the theory that spindles in task-related regions promote the neural plasticity necessary for motor memory consolidation. We propose that spindles in task-related regions may be more sensitive biomarkers of learning and sleep-dependent memory consolidation than those occurring elsewhere.
睡眠纺锤波在依赖睡眠的记忆巩固中起着关键作用。尽管纺锤波可广泛出现在整个皮质，但它们往往是局灶性的。局灶性纺锤波可能会促进不同神经回路中的可塑性，以巩固特定类型的记忆。在本研究中，我们在白天小睡期间同时采集了25名健康成年人（6名女性）的脑电图（EEG）和脑磁图（MEG）数据，以研究学习手指敲击运动序列任务（MST）是否会优先增加任务执行期间参与的皮质区域内的纺锤波密度（#/分钟），以及这些与任务相关的纺锤波增加是否能预测小睡后测量的表现改善情况。我们采用了一种新颖的算法，利用来自磁共振成像（MRI）的解剖学约束将EEG/MEG信号投影到源空间，并在皮质区域检测纺锤波。与基线小睡相比，MST训练优先增加了学习时参与区域的纺锤波密度，这反过来又预测了小睡后的表现改善。训练期间的学习与小睡后表现的改善没有相关性，这表明它们反映的是不同的过程。它们也有不同的神经关联。训练期间的学习与运动执行区域的纺锤波密度增加相关，而小睡后的表现改善与运动规划区域的增加相关。我们推测运动执行区域的纺锤波代表记忆，而规划区域的纺锤波则增强未来的表现。我们的研究结果表明，纺锤波的表达受先前学习的影响，并支持这样一种理论，即与任务相关区域的纺锤波促进了运动记忆巩固所需的神经可塑性。我们提出，与任务相关区域的纺锤波可能比其他地方出现的纺锤波更敏感，是学习和依赖睡眠的记忆巩固的生物标志物。
