基于功能影像学探讨百会治疗失眠的中枢机制

百会为治疗失眠的效穴,临床使用频率高。功能影像学,广义上包括多种成像技术,狭义主要指功能性磁共振成像(fMRI),数据分析方法分为功能分离和功能整合两类,试验设计方案包括任务态(Tb-fMRI)与静息态(Rs-fMRI),静息态因操作简便且能直观反映针刺持续和累积效应而被广泛应用。多项fMRI研究表明,失眠患者在视觉区、感觉运动区、情绪相关脑区等存在局部功能异常,针刺百会单穴或组穴可引起特定脑区如顶叶、额叶、颞叶等的改变,从而改善睡眠。针刺单穴百会主要集中在Rs-fMRI局部一致性(ReHo)、比率低频振幅(fALFF)研究,而针刺百会组穴研究从Rs-fMRI局部一致性(ReHo)、度中心度(DC)、种子连接(FC),以及Tb-fMRI比率低频振幅(fALFF)等方面展开,研究发现不同研究方法和穴位组合下的脑区激活改变存在差异,且针刺百会组穴所调控脑区多于单穴针刺,体现了百会对失眠、认知和情绪的调节作用以及腧穴间的协同作用。然而,针刺百会引起的中枢信号改变复杂,功能影像作为评估失眠的中枢指标虽有潜力,但仍需更规范、深入的研究。

The effect of lithium on resting-state brain networks in patients with bipolar depression

Objective： Although lithium has been a commonly prescribed neurotrophic/neuroprotective mood-stabilizing agents, its effect on spontaneous brain activity in patients with bipolar depression remains unclear. The aim of this study is to reveal the basic mechanism underlying the pathological influences of lithium on resting-state brain function of bipolar depression patients. Methods：97 subjects including 9 bipolar depression patients with lithium treatment, 19 bipolar depression patients without lithium treatment and 69 healthy controls, were recruited to participate in this study. Amplitude of low-frequency fluctuation （ ALFF ） and fractional amplitude of low-frequency fluctuation （ fALFF） were used to capture the changes of spontane-ous brain activity among different groups. In addition, further analysis in terms of Hamilton Depression Rating Scale, the number of depressive episodes, and illness duration in pooled bipolar depression patients were conducted, which combined FLEF and fALEF to identify the basic neural features of bipolar depression patients. Results： It was observed from the imaging results that both the bipolar depression patients receiving lithium treatment and healthy control subjects showed signifi-cantly decreased ALFF/fALFF values in the right anterior cingulate cortex and right middle frontal gyrus compared to that from the bipolar depression patients without lithium treatmetn. The ALFF values of the right＆amp;nbsp;middle temporal gyrus was also found to be negative related to the number of depressive episode and the total episodes. Conclusions：Our findings suggested that the bipolar depression subjects were identified to have ab-normal ALFF/ fALFF in the corticolimbic systems, in-cluding regions like right anterior cingulate cortex, bilateral middle frontal gyrus, right orbital frontal gyrus, and right middle temporal gyrus. In addition, it was also revealed that the decreased ALFF/fALFF in the right anterior cingulate cortex and right middle frontal gyrus might be a biomarker that is related to the lithium effects.

Spontaneous activity in medial orbitofrontal cortex correlates with trait anxiety in healthy male adults

Medial orbitofrontal cortex （mOFC） abnormalities have been observed in various anxiety disorders. However, the relationship between mOFC activity and anxiety among the healthy population has not been fully examined. Here, we conducted a resting state functional magnetic resonance imaging （R-fMRI） study with 56 healthy male adults from the Nathan Kline Institute/Rockland Sample （NKI-RS） to examine the relationship between the fractional amplitude of low-frequency fluctuation （fALFF） signals and trait anxiety across the whole brain. A Louvain method for module detection based on graph theory was further employed in the automated functional subdivision to explore subregional correlates of trait anxiety. The results showed that trait anxiety was related to fALFF in the mOFC. Additionally, the resting-state functional connectivity （RSFC） between the right subregions of the mOFC and the precuneus was correlated with trait anxiety. These findings provided evidence about the involvement of the mOFC in anxiety processing among the healthy population.