Tracking transient changes in the intrinsic neural frequency architecture: Oxytocin facilitates non-harmonic relationships between alpha and theta rhythms in the resting brain
Tracking transient changes in the intrinsic neural frequency architecture: Oxytocin facilitates non-harmonic relationships between alpha and theta rhythms in the resting brain
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DOI：
10.1016/j.psyneuen.2021.105397
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发表时间：
2021-09-01
影响因子：
3.7
通讯作者：
Daniels, Nicky
中科院分区：
文献类型：
--
作者：
Alaerts, Kaat;Taillieu, Aymara;Daniels, Nicky
振荡神经节律的峰值频率的移位被认为是大脑中实现跨频率耦合和解耦的主要机制。这个概念是基于数学现实，即当神经振荡的峰值频率形成谐波2:1关系时(例如，f(2) =f(1)/2)，神经振荡才能完全同步。另一方面，非谐波交叉频率关系（基于非理性黄金平均数1.618）。1)，提供最高的生理上可能的非同步状态（减少虚假，嘈杂，背景耦合的发生），因此有望表征大脑的静息状态，其中没有选择性信息处理发生。本研究旨在评估α (8- 14hz)和θ (4- 8hz)波段峰值频率之间1.6:1非谐波和2:1谐波关系的短暂发生是否受到单剂量催产素（OT）或安慰剂鼻内给药的影响，这两种关系分别促进了振荡节律之间的脱钩或耦合状态。为此，对96名健康成年男性进行了连续静息状态脑电图（开眼5分钟，19个电极）。经OT鼻喷后，α和θ峰频率之间的非谐波跨频结构的瞬态形成显著增加，表明OT对减少静息状态时本征的杂散（噪声）背景相位同步有一定的作用。作为一个整体，OT组也显示出高频心率变异性的显著增加和低频心率变异性的减少，证实了OT在平衡副交感神经驱动方面的稳态作用。总的来说，提出了非谐波交叉频率配置，为健康的神经网络奠定了基础，使其有机会从静止状态有效地过渡到活动状态。因此，观察到的OT对交叉频率动力学的影响被解释为反映了OT在增加固有脑电图神经频率结构的信噪特性方面的稳态作用，即通过排除静息大脑中神经节律之间“嘈杂”，不需要的，虚假耦合的发生。
Shifts in the peak frequencies of oscillatory neural rhythms have been put forward as a principal mechanism by which cross-frequency coupling and decoupling is implemented in the brain. This notion is based on the mathematical reality that neural oscillations can only fully synchronize when their peak frequencies form harmonic 2:1 relationships (e.g., f(2) =f(1)/2). Non-harmonic cross-frequency relationships, on the other hand (based on the irrational golden mean 1.618.:1), provide the highest physiologically possible desynchronized state (reducing the occurrence of spurious, noisy, background coupling), and are therefore anticipated to characterize the resting state of the brain, in which no selective information processing takes place. The present study sought to assess whether the transient occurrence of 1.6:1 non-harmonic and 2:1 harmonic relationships between peak frequencies in the alpha (8-14 Hz) and theta (4-8 Hz) bands - respectively facilitating states of decoupling or coupling between oscillatory rhythms - are impacted by the intranasal administration of a single-dose of oxytocin (OT) or placebo. To do so, continuous resting-state electroencephalography (5 min eyes open, 19 electrodes) was obtained from 96 healthy adult men before and after nasal spray administration. The transient formation of non-harmonic cross-frequency configurations between alpha and theta peak frequencies was significantly increased after OT nasal spray administration, indicating an effect of OT on reducing the intrinsic occurrence of spurious (noisy) background phase synchronizations during resting-state. As a group, the OT group also showed a significant parallel increase in high-frequency and decrease in low-frequency heart rate variability, confirming a homeostatic role of OT in balancing parasympathetic drive. Overall, non-harmonic cross-frequency configurations have been put forward to lay the ground for a healthy neural network allowing the opportunity for an efficient transition from resting state to activity. The observed effects of OT on cross-frequency dynamics are therefore interpreted to reflect a homeostatic role of OT in increasing the signal-to-noise properties of the intrinsic EEG neural frequency architecture, i.e., by precluding the occurrence of `noisy', unwanted, spurious couplings among neural rhythms in the resting brain.