Zhong Weiwei, Ciatipis Mareva, Wolfenstetter Thérèse, Jessberger Jakob, Müller Carola, Ponsel Simon, Yanovsky Yevgenij, Brankačk Jurij, Tort Adriano B L, Draguhn Andreas
Institute for Physiology and Pathophysiology, University of Heidelberg, 69120 Heidelberg, Germany.
Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, 230022 Hefei, China.
Proc Natl Acad Sci U S A. 2017 Apr 25;114(17):4519-4524. doi: 10.1073/pnas.1617249114. Epub 2017 Apr 10.
Theta oscillations (4-12 Hz) are thought to provide a common temporal reference for the exchange of information among distant brain networks. On the other hand, faster gamma-frequency oscillations (30-160 Hz) nested within theta cycles are believed to underlie local information processing. Whether oscillatory coupling between global and local oscillations, as showcased by theta-gamma coupling, is a general coding mechanism remains unknown. Here, we investigated two different patterns of oscillatory network activity, theta and respiration-induced network rhythms, in four brain regions of freely moving mice: olfactory bulb (OB), prelimbic cortex (PLC), parietal cortex (PAC), and dorsal hippocampus [cornu ammonis 1 (CA1)]. We report differential state- and region-specific coupling between the slow large-scale rhythms and superimposed fast oscillations. During awake immobility, all four regions displayed a respiration-entrained rhythm (RR) with decreasing power from OB to CA1, which coupled exclusively to the 80- to 120-Hz gamma subband (γ). During exploration, when theta activity was prevailing, OB and PLC still showed exclusive coupling of RR with γ and no theta-gamma coupling, whereas PAC and CA1 switched to selective coupling of theta with 40- to 80-Hz (γ) and 120- to 160-Hz (γ) gamma subbands. Our data illustrate a strong, specific interaction between neuronal activity patterns and respiration. Moreover, our results suggest that the coupling between slow and fast oscillations is a general brain mechanism not limited to the theta rhythm.
θ振荡（4-12赫兹）被认为为远距离脑网络之间的信息交换提供了一个共同的时间参考。另一方面，嵌套在θ周期内的更快的γ频率振荡（30-160赫兹）被认为是局部信息处理的基础。θ-γ耦合所展示的全局和局部振荡之间的振荡耦合是否是一种普遍的编码机制仍然未知。在这里，我们研究了自由活动小鼠的四个脑区（嗅球（OB）、前边缘皮层（PLC）、顶叶皮层（PAC）和背侧海马体[海马1区（CA1）]）中两种不同模式的振荡网络活动，即θ振荡和呼吸诱导的网络节律。我们报告了慢的大规模节律与叠加的快速振荡之间不同的状态和区域特异性耦合。在清醒不动期间，所有四个区域都表现出一种呼吸夹带节律（RR），其功率从OB到CA1逐渐降低，该节律仅与80至120赫兹的γ子带（γ）耦合。在探索期间，当θ活动占主导时，OB和PLC仍然表现出RR与γ的排他性耦合，且没有θ-γ耦合，而PAC和CA1则切换为θ与40至80赫兹（γ）和120至160赫兹（γ）γ子带的选择性耦合。我们的数据说明了神经元活动模式与呼吸之间强烈的、特定的相互作用。此外，我们的结果表明，慢振荡和快振荡之间的耦合是一种不限于θ节律的普遍脑机制。
