Páscoa Dos Santos Francisco, Verschure Paul F M J
Eodyne Systems SL, Barcelona, Spain.
Department of Information and Communication Technologies, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
PLoS Comput Biol. 2025 Jan 6;21(1):e1012723. doi: 10.1371/journal.pcbi.1012723. eCollection 2025 Jan.
Although the primary function of excitatory-inhibitory (E-I) homeostasis is the maintenance of mean firing rates, the conjugation of multiple homeostatic mechanisms is thought to be pivotal to ensuring edge-of-bifurcation dynamics in cortical circuits. However, computational studies on E-I homeostasis have focused solely on the plasticity of inhibition, neglecting the impact of different modes of E-I homeostasis on cortical dynamics. Therefore, we investigate how the diverse mechanisms of E-I homeostasis employed by cortical networks shape oscillations and edge-of-bifurcation dynamics. Using the Wilson-Cowan model, we explore how distinct modes of E-I homeostasis maintain stable firing rates in models with varying levels of input and how it affects circuit dynamics. Our results confirm that E-I homeostasis can be leveraged to control edge-of-bifurcation dynamics and that some modes of homeostasis maintain mean firing rates under higher levels of input by modulating the distance to the bifurcation. Additionally, relying on multiple modes of homeostasis ensures stable activity while keeping oscillation frequencies within a physiological range. Our findings tie relevant features of cortical networks, such as E-I balance, the generation of gamma oscillations, and edge-of-bifurcation dynamics, under the framework of firing-rate homeostasis, providing a mechanistic explanation for the heterogeneity in the distance to the bifurcation found across cortical areas. In addition, we reveal the functional benefits of relying upon different homeostatic mechanisms, providing a robust method to regulate network dynamics with minimal perturbation to the generation of gamma rhythms and explaining the correlation between inhibition and gamma frequencies found in cortical networks.
尽管兴奋性-抑制性（E-I）稳态的主要功能是维持平均放电率，但多种稳态机制的结合被认为对于确保皮层回路中的分岔边缘动态至关重要。然而，关于E-I稳态的计算研究仅聚焦于抑制的可塑性，而忽略了不同模式的E-I稳态对皮层动态的影响。因此，我们研究皮层网络采用的多种E-I稳态机制如何塑造振荡和分岔边缘动态。使用威尔逊-考恩模型，我们探讨了不同模式的E-I稳态如何在具有不同输入水平的模型中维持稳定的放电率，以及它如何影响回路动态。我们的结果证实，可以利用E-I稳态来控制分岔边缘动态，并且某些稳态模式通过调节到分岔的距离在更高输入水平下维持平均放电率。此外，依赖多种稳态模式可确保稳定活动，同时将振荡频率保持在生理范围内。我们的研究结果将皮层网络的相关特征，如E-I平衡、伽马振荡的产生和分岔边缘动态，纳入放电率稳态的框架下，为不同皮层区域到分岔距离的异质性提供了一个机制性解释。此外，我们揭示了依赖不同稳态机制的功能优势，提供了一种以最小程度干扰伽马节律产生来调节网络动态的稳健方法，并解释了皮层网络中发现的抑制与伽马频率之间的相关性。
