Data_Sheet_1_Local field potentials and single unit dynamics in motor cortex of unconstrained macaques during different behavioral states.pdf

Different sleep stages have been shown to be vital for a variety of brain functions, including learning, memory, and skill consolidation. However, our understanding of neural dynamics during sleep and the role of prominent LFP frequency bands remain incomplete. To elucidate such dynamics and differences between behavioral states we collected multichannel LFP and spike data in primary motor cortex of unconstrained macaques for up to 24 h using a head-fixed brain-computer interface (Neurochip3). Each 8-s bin of time was classified into awake-moving (Move), awake-resting (Rest), REM sleep (REM), or non-REM sleep (NREM) by using dimensionality reduction and clustering on the average spectral density and the acceleration of the head. LFP power showed high delta during NREM, high theta during REM, and high beta when the animal was awake. Cross-frequency phase-amplitude coupling typically showed higher coupling during NREM between all pairs of frequency bands. Two notable exceptions were high delta-high gamma and theta-high gamma coupling during Move, and high theta-beta coupling during REM. Single units showed decreased firing rate during NREM, though with increased short ISIs compared to other states. Spike-LFP synchrony showed high delta synchrony during Move, and higher coupling with all other frequency bands during NREM. These results altogether reveal potential roles and functions of different LFP bands that have previously been unexplored.

多项研究已证实，不同睡眠时相对学习、记忆与技能巩固等多种大脑功能至关重要。然而，目前学界对于睡眠期间的神经动力学特征，以及关键局部场电位（Local Field Potential, LFP）频段的功能角色，仍未形成完整认知。为阐明此类动力学特征与行为状态间的差异，本研究借助头部固定式脑机接口Neurochip3，在最长24小时的采集周期内，于自由活动猕猴的初级运动皮层采集了多通道局部场电位与神经元锋电位数据。研究人员通过对平均功率谱密度与头部加速度进行降维和聚类分析，将每段时长8秒的时间窗划分为四种状态：活动觉醒（Move）、静息觉醒（Rest）、快速眼动睡眠（REM）与非快速眼动睡眠（NREM）。局部场电位功率分析显示，NREM睡眠期间δ频段功率显著升高，REM睡眠期间θ频段功率占优，而觉醒状态下则以β频段功率为主。跨频段相位振幅耦合（Cross-frequency Phase-Amplitude Coupling, CFC）通常显示，NREM睡眠期间所有频段组合间的耦合强度均高于其他状态，但存在两处显著例外：活动觉醒状态下存在δ-高频γ频段与θ-高频γ频段的强耦合，REM睡眠期间则出现θ-β频段的强耦合。单神经元单位放电频率在NREM睡眠期间有所降低，但与其他状态相比，其短峰间期（Inter-Spike Interval, ISI）的占比有所提升。锋电位-局部场电位同步性分析显示，活动觉醒状态下δ频段同步性较强，而NREM睡眠期间锋电位与其余所有频段的耦合强度均更高。综上，本研究结果揭示了此前未被探明的各类局部场电位频段潜在功能与作用。