Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Mainz, Germany.
Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center Mainz, Germany.
Cereb Cortex. 2019 Jul 22;29(8):3201-3210. doi: 10.1093/cercor/bhy188.
Anxiety reduction through mere expectation of anxiolytic treatment effects (placebo anxiolysis) has enormous clinical importance. Recent behavioral and electrophysiological data suggest that placebo anxiolysis involves reduced vigilance and enhanced internalization of attention; however, the underlying neurobiological mechanisms are not yet clear. Given the fundamental function of intrinsic connectivity networks (ICNs) in basic cognitive processes, we investigated ICN activity patterns associated with externally and internally directed mental states under the influence of an anxiolytic placebo medication. Based on recent findings, we specifically analyzed the functional role of the rostral anterior cingulate cortex (rACC) in coordinating placebo-dependent cue-related (phasic) and cue-unrelated (sustained) network activity. Under placebo, we observed a down-regulation of the entire salience network (SN), particularly in response to threatening cues. The rACC exhibited enhanced cue-unrelated functional connectivity (FC) with the SN, which correlated with reductions in tonic arousal and anxiety. Hence, apart from the frequently reported modulation of aversive cue responses, the rACC appears to be crucially involved in exerting a tonically dampening control over salience-responsive structures. In line with a more internally directed mental state, we also found enhanced FC within the default mode network (DMN), again predicting reductions in anxiety under placebo.
通过仅仅预期抗焦虑治疗效果（安慰剂抗焦虑）来减轻焦虑具有巨大的临床意义。最近的行为和电生理数据表明，安慰剂抗焦虑涉及警觉性降低和注意力内化增强；然而，潜在的神经生物学机制尚不清楚。鉴于内在连通性网络（ICNs）在基本认知过程中的基本功能，我们研究了在抗焦虑安慰剂药物影响下与外部和内部导向的心理状态相关的 ICN 活动模式。基于最近的发现，我们特别分析了额前扣带皮层（rACC）在协调安慰剂依赖的线索相关（相位）和线索无关（持续）网络活动中的功能作用。在安慰剂作用下，我们观察到整个显着性网络（SN）的下调，特别是对威胁性线索的下调。rACC 与 SN 之间表现出增强的线索无关功能连接（FC），这与紧张性唤醒和焦虑的降低相关。因此，除了经常报道的对厌恶线索反应的调节外，rACC 似乎还参与对显着性反应结构进行紧张抑制控制。与更内部导向的心理状态一致，我们还发现默认模式网络（DMN）内的 FC 增强，再次预测安慰剂下焦虑的降低。
