Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
Centre for Sleep & Cognition & Centre for Translational Magnetic Resonance Research, Yong Loo Lin School of Medicine, Singapore, Singapore.
Nat Commun. 2021 Nov 4;12(1):6373. doi: 10.1038/s41467-021-26704-y.
Large-scale biophysical circuit models provide mechanistic insights into the micro-scale and macro-scale properties of brain organization that shape complex patterns of spontaneous brain activity. We developed a spatially heterogeneous large-scale dynamical circuit model that allowed for variation in local synaptic properties across the human cortex. Here we show that parameterizing local circuit properties with both anatomical and functional gradients generates more realistic static and dynamic resting-state functional connectivity (FC). Furthermore, empirical and simulated FC dynamics demonstrates remarkably similar sharp transitions in FC patterns, suggesting the existence of multiple attractors. Time-varying regional fMRI amplitude may track multi-stability in FC dynamics. Causal manipulation of the large-scale circuit model suggests that sensory-motor regions are a driver of FC dynamics. Finally, the spatial distribution of sensory-motor drivers matches the principal gradient of gene expression that encompasses certain interneuron classes, suggesting that heterogeneity in excitation-inhibition balance might shape multi-stability in FC dynamics.
大规模生物物理电路模型为大脑组织的微观和宏观特性提供了机理见解，这些特性塑造了自发脑活动的复杂模式。我们开发了一种具有空间异质性的大规模动力电路模型，允许在人类大脑皮层中局部突触特性发生变化。在这里，我们表明，用解剖学和功能梯度来参数化局部电路特性，可以产生更真实的静态和动态静息状态功能连接（FC）。此外，经验和模拟的 FC 动力学表明，FC 模式的急剧转变非常相似，这表明存在多个吸引子。时变的区域 fMRI 幅度可能会追踪 FC 动力学的多稳定性。对大规模电路模型的因果操作表明，感觉运动区域是 FC 动力学的驱动力。最后，感觉运动驱动的空间分布与包含某些中间神经元类别的基因表达的主要梯度相匹配，这表明兴奋-抑制平衡的异质性可能会影响 FC 动力学的多稳定性。
