Connectome Lab, Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, De Boelelaan 1081-1087, Amsterdam, The Netherlands.
Research Center for Motor Control and Neuroplasticity, KU Leuven, Tervuursevest 101 - Leuven, Belgium.
Cereb Cortex. 2019 Dec 17;29(11):4646-4653. doi: 10.1093/cercor/bhy342.
Functional connectivity is defined as the statistical dependency of neurophysiological activity between 2 separate brain areas. To investigate the biological characteristics of resting-state functional connectivity (rsFC)-and in particular the significance of connection-wise variation in time-series correlations-rsFC was compared with strychnine-based connectivity measured in the macaque. Strychnine neuronography is a historical technique that induces activity in cortical areas through means of local administration of the substance strychnine. Strychnine causes local disinhibition through GABA suppression and leads to subsequent activation of functional pathways. Multiple resting-state fMRI recordings were acquired in 4 macaques (examining in total 299 imaging runs) from which a group-averaged rsFC matrix was constructed. rsFC was observed to be higher (P < 0.0001) between region-pairs with a strychnine-based connection as compared with region-pairs with no strychnine-based connection present. In particular, higher resting-state connectivity was observed in connections that were relatively stronger (weak < moderate < strong; P < 0.01) and in connections that were bidirectional (P < 0.0001) instead of unidirectional in strychnine-based connectivity. Our results imply that the level of correlation between brain areas as extracted from resting-state fMRI relates to the strength of underlying interregional functional pathways.
功能连接被定义为两个独立脑区之间神经生理活动的统计依赖性。为了研究静息态功能连接（rsFC）的生物学特征——特别是时间序列相关性的连接变化的意义——我们将 rsFC 与在猕猴中测量的基于士的宁的连接进行了比较。士的宁神经元图是一种历史悠久的技术，通过局部给予士的宁物质来诱导皮质区域的活动。士的宁通过 GABA 抑制导致局部去抑制，并导致随后的功能途径激活。从 4 只猕猴（总共检查了 299 次成像运行）中获得了多个静息状态 fMRI 记录，并构建了一个群组平均的 rsFC 矩阵。与没有士的宁连接的区域对相比，具有基于士的宁的连接的区域对之间的 rsFC 更高（P < 0.0001）。特别是，在相对较强（弱<中等<强；P < 0.01）的连接以及双向（P < 0.0001）而不是单向的连接中观察到更高的静息状态连接。我们的结果表明，从静息状态 fMRI 中提取的脑区之间的相关水平与潜在的区域间功能途径的强度有关。
