Li XiuPing, Li ZhengHong, Yang WanMei, Wu Zhen, Wang JunSong
School of Biomedical Engineering, Tianjin Medical University, Tianjin, China.
Department of Psychology, Tianjin University of Technology and Education, Tianjin, China.
Front Syst Neurosci. 2022 Feb 21;16:723237. doi: 10.3389/fnsys.2022.723237. eCollection 2022.
The Wilson-Cowan model can emulate gamma oscillations, and thus is extensively used to research the generation of gamma oscillations closely related to cognitive functions. Previous studies have revealed that excitatory and inhibitory inputs to the model can modulate its gamma oscillations. Inhibitory and excitatory self-feedback loops are important structural features of the model, however, its functional role in the regulation of gamma oscillations in the model is still unclear. In the present study, bifurcation analysis and spectrum analysis are employed to elucidate the regulating mechanism of gamma oscillations underlined by the inhibitory and excitatory self-feedback loops, especially how the two self-feedback loops cooperate to generate the gamma oscillations and regulate the oscillation frequency. The present results reveal that, on one hand, the inhibitory self-feedback loop is not conducive to the generation of gamma oscillations, and increased inhibitory self-feedback strength facilitates the enhancement of the oscillation frequency. On the other hand, the excitatory self-feedback loop promotes the generation of gamma oscillations, and increased excitatory self-feedback strength leads to the decrease of oscillation frequency. Finally, theoretical analysis is conducted to provide explain on how the two self-feedback loops play a crucial role in the generation and regulation of neural oscillations in the model. To sum up, Inhibitory and excitatory self-feedback loops play a complementary role in generating and regulating the gamma oscillation in Wilson-Cowan model, and cooperate to bidirectionally regulate the gamma-oscillation frequency in a more flexible manner. These results might provide testable hypotheses for future experimental research.
威尔逊-考恩模型能够模拟伽马振荡，因此被广泛用于研究与认知功能密切相关的伽马振荡的产生。先前的研究表明，该模型的兴奋性和抑制性输入可以调节其伽马振荡。抑制性和兴奋性自反馈回路是该模型的重要结构特征，然而，其在模型中对伽马振荡调节的功能作用仍不清楚。在本研究中，采用分岔分析和频谱分析来阐明由抑制性和兴奋性自反馈回路所强调的伽马振荡的调节机制，特别是这两个自反馈回路如何协同作用以产生伽马振荡并调节振荡频率。目前的结果表明，一方面，抑制性自反馈回路不利于伽马振荡的产生，抑制性自反馈强度的增加有助于振荡频率的提高。另一方面，兴奋性自反馈回路促进伽马振荡的产生，兴奋性自反馈强度的增加导致振荡频率的降低。最后，进行理论分析以解释这两个自反馈回路如何在模型中神经振荡的产生和调节中发挥关键作用。综上所述，抑制性和兴奋性自反馈回路在威尔逊-考恩模型中伽马振荡的产生和调节中发挥着互补作用，并以更灵活的方式协同双向调节伽马振荡频率。这些结果可能为未来的实验研究提供可检验的假设。
