Graduate School of Life Science, University of Hyogo, Japan.
BK21 PLUS Project for Medical Science, Department of Nuclear Medicine, Department of Radiology, Department of Psychiatry, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Neuroimage. 2017 Apr 1;149:153-164. doi: 10.1016/j.neuroimage.2017.01.075. Epub 2017 Feb 1.
The configuration of the human brain system at rest, which is in a transitory phase among multistable states, remains unknown. To investigate the dynamic systems properties of the human brain at rest, we constructed an energy landscape for the state dynamics of the subcortical brain network, a critical center that modulates whole brain states, using resting state fMRI. We evaluated alterations in energy landscapes following perturbation in network parameters, which revealed characteristics of the state dynamics in the subcortical brain system, such as maximal number of attractors, unequal temporal occupations, and readiness for reconfiguration of the system. Perturbation in the network parameters, even those as small as the ones in individual nodes or edges, caused a significant shift in the energy landscape of brain systems. The effect of the perturbation on the energy landscape depended on the network properties of the perturbed nodes and edges, with greater effects on hub nodes and hubs-connecting edges in the subcortical brain system. Two simultaneously perturbed nodes produced perturbation effects showing low sensitivity in the interhemispheric homologous nodes and strong dependency on the more primary node among the two. This study demonstrated that energy landscape analysis could be an important tool to investigate alterations in brain networks that may underlie certain brain diseases, or diverse brain functions that may emerge due to the reconfiguration of the default brain network at rest.
人类大脑在休息时的系统结构处于多种稳定状态之间的过渡阶段，其状态仍然未知。为了研究人类大脑在休息时的动态系统特性，我们使用静息态 fMRI 构建了一个亚皮质脑网络状态动力学的能量景观，该网络是调节整个大脑状态的关键中心。我们评估了网络参数扰动后能量景观的变化，揭示了亚皮质脑系统状态动力学的特征，例如吸引子的最大数量、时间占用的不平等以及系统重新配置的准备状态。即使是单个节点或边缘的微小网络参数扰动，也会导致大脑系统能量景观发生显著变化。扰动对能量景观的影响取决于受扰节点和边缘的网络特性，对亚皮质脑系统中的枢纽节点和枢纽连接边缘的影响更大。同时扰动两个节点会产生扰动效应，在大脑半球间的同源节点中表现出低敏感性，而对两个节点中更为主要的节点依赖性更强。本研究表明，能量景观分析可能是一种重要的工具，可以研究可能导致某些脑部疾病的大脑网络变化，或由于默认大脑网络在休息时的重新配置而出现的各种大脑功能。
