School of Life Science and Technology, Harbin Institute of Technology, Harbin, 150001, China.
Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology, Harbin, 150001, China.
Brain Struct Funct. 2023 Dec;228(9):2115-2124. doi: 10.1007/s00429-023-02708-w. Epub 2023 Sep 21.
Spontaneous brain activity exhibits a highly structured modular organization that varies across individuals and reconfigures over time. Although it has been proposed that brain organization is shaped by an economic trade-off between minimizing costs and facilitating efficient information transfer, it remains untested whether modular variability and its changes during unconscious conditions might be constrained by the economy of brain organization. We acquired functional MRI and FDG-PET in rats under three different levels of consciousness induced by propofol administration. We examined alterations in brain modular variability during loss of consciousness from mild sedation to deep anesthesia. We also investigated the relationships between modular variability with glucose metabolism and functional connectivity strength as well as their alterations during unconsciousness. We observed that modular variability increased during loss of consciousness. Critically, across-individual modular variability is oppositely associated with functional connectivity strength and cerebral metabolism, and with deepening dosage of anesthesia, becoming increasingly dependent on basal metabolism over functional connectivity. These results suggested that, propofol-induced unconsciousness may lead to brain modular reorganization, which are putatively shaped by re-negotiations between energetic resources and communication efficiency.
自发性脑活动表现出高度结构化的模块组织，这种组织在个体之间存在差异，并随时间重新配置。虽然有人提出大脑组织的形成是通过在最小化成本和促进有效信息传递之间进行经济权衡来实现的，但尚未验证在无意识状态下模块的可变性及其变化是否可能受到大脑组织经济性的限制。我们在大鼠中使用丙泊酚诱导的三种不同意识水平获得了功能 MRI 和 FDG-PET。我们研究了在从轻度镇静到深度麻醉的意识丧失过程中，大脑模块可变性的变化。我们还研究了模块可变性与葡萄糖代谢和功能连接强度之间的关系，以及它们在无意识状态下的变化。我们观察到在意识丧失期间模块可变性增加。重要的是，跨个体的模块可变性与功能连接强度和大脑代谢呈相反相关，并且随着麻醉剂量的加深，模块可变性越来越依赖于基础代谢而不是功能连接。这些结果表明，丙泊酚诱导的无意识可能导致大脑模块重新组织，这可能是通过能量资源和通信效率之间的重新协商形成的。
