Mental Health Center, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
Department of Brain Functioning Research, Hangzhou Seventh People's Hospital, Hangzhou, Zhejiang, China.
Schizophr Bull. 2019 Jun 18;45(4):902-910. doi: 10.1093/schbul/sby138.
Bipolar disorder (BD) is a complex psychiatric disorder characterized by dominant symptom swings across different phases (manic, depressive, and euthymic). Different symptoms in BD such as abnormal episodic memory recall and psychomotor activity have been related to alterations in different regions, ie, hippocampus and motor cortex. How the abnormal regional distribution of neuronal activity relates to specific symptoms remains unclear, however. One possible neuronal mechanism of the relationship is the alteration of the global distribution of neuronal activity manifested in specific local regions; this can be measured as the correlation between the global signal (GS) and local regions. To understand the GS and its relationship to psychopathological symptoms, we here investigated the alteration of both GS variance and its regional topography in healthy controls and 3 phases of BD. We found that the variance of GS showed no significant difference between the 4 groups. In contrast, the GS topography was significantly altered in the different phases of BD, ie, the regions showing abnormally strong topographical GS contribution changed from hippocampus (and parahippocampus/fusiform gyrus) in depression to motor cortex in mania. Importantly, topographical GS changes in these regions correlated with psychopathological measures in both depression and mania. Taken together, our findings demonstrate the central importance of GS topography for psychopathological symptoms. This sheds lights on the neuronal mechanisms of specific psychopathological symptoms in BD, and its relevance in the relationship between global and local neuronal activities for behavior in general.
双相障碍（BD）是一种复杂的精神障碍，其特征是在不同阶段（躁狂、抑郁和轻躁狂）出现主导症状波动。BD 中的不同症状，如异常发作性记忆回忆和精神运动活动，与不同区域的改变有关，即海马体和运动皮层。然而，异常区域神经元活动的分布与特定症状之间的关系尚不清楚。神经元活动的这种异常局部分布与特定症状相关的一种可能的神经元机制是神经元活动的全局分布的改变，这可以表现为全局信号（GS）与局部区域之间的相关性。为了了解 GS 及其与精神病理学症状的关系，我们在这里研究了健康对照组和 BD 的 3 个阶段中 GS 方差及其局部拓扑结构的变化。我们发现，GS 的方差在 4 组之间没有显著差异。相比之下，GS 的拓扑结构在 BD 的不同阶段发生了显著改变，即在抑郁时表现出异常强烈的拓扑 GS 贡献的区域从海马体（和海马旁回/梭状回）改变为躁狂时的运动皮层。重要的是，这些区域的 GS 拓扑变化与抑郁和躁狂时的精神病理学测量相关。总之，我们的研究结果表明，GS 拓扑结构对于精神病理学症状具有重要意义。这揭示了 BD 中特定精神病理学症状的神经元机制，以及其在全局和局部神经元活动之间关系对于一般行为的相关性。
