The short allele of the serotonin-transporter gene is associated with higher risk for anxiety and depression in Caucasians, but this association is still unclear in Asians. Here, we addressed this issue using behavioral and multi-modal MRI approaches in a large group of healthy Han Chinese participants (n = 233). In contrast to findings in Caucasians, we found that long-allele (L) carriers had higher anxiety scores. In another group (n = 64) experiencing significant levels of depression or anxiety, the L-allele frequency was also significantly higher. In healthy participants, L-carriers had reduced functional and anatomical connectivity between the amygdala and prefrontal cortex (PFC), which was correlated with anxiety or depression scores. Our findings demonstrated that in Chinese Han participants, in contrast to Caucasians, the L-allele confers vulnerability to anxiety or depression and weakens top-down emotional control between the PFC and amygdala. Therefore, ethnic background should be taken into account in gene-related studies and their potential clinical applications.
Increasing evidence shows that the human brain is a highly self-organized system that shows attributes of smallworldness,hierarchy and modularity.The "connectome" was conceived several years ago to identify the underpinning physical connectivities of brain networks.The need for an integration of multi-spatial and-temporal approaches is becoming apparent.Therefore,the "Brainnetome"(brain-net-ome) project was proposed.Diffusion magnetic resonance imaging(dMRI) is a non-invasive way to study the anatomy of brain networks.Here,we review the principles of dMRI,its methodologies,and some of its clinical applications for the Brainnetome.Future research in this field is discussed.
The functional brain network using blood-oxygen-level-dependent(BOLD) functional magnetic resonance imaging(fMRI) has revealed the potentials for probing brain architecture,as well as for identifying clinical biomarkers for brain diseases.In the general context of Brainnetome,this review focuses on the development of approaches for modeling and analyzing functional brain networks with BOLD fMRI.The prospects for these approaches are also discussed.
Auditory verbal hallucination(AVH)is emphasized as a pathological hallmark of schizophrenia.Neuroimaging studies provide evidence linking AVH to overlapping functional abnormalities in distributed networks.However,no clear conclusion has still been reached.This study aimed to further explore the brain activity of patients with schizophrenia having AVH from both local activity(LA)and functional connectivity(FC)insights,while excluding confounding factors from other positive symptoms.A total of 42 patients with AVH(AVH patients group,APG),26 without AVH(non-AVH patients group,NPG),and 82 normal controls(NC)underwent resting-state functional magnetic resonance imaging(fMRI).LA measures,including regional homogeneity(ReHo)and fractional amplitude of low-frequency fluctuations(fALFF),and FC measures were evaluated to understand the neuroimaging mechanism of AVH.APG showed increased ReHo and fALFF in the bilateral putamen(Put)compared with NPG and NC.FC analysis(using bilateral putamen as seeds)revealed that all patients showed abnormal FC of multiple resting state network regions,including the anterior and post cingulate cortex,middle frontal gyrus,inferior parietal gyrus,and left angular gyrus.Interestingly,APG showed significantly decreased FC of insula extending to the superior temporal gyrus and inferior frontal gyrus compared with NPG and NC.The present findings suggested a significant correlation of abnormal LA and dysfunctional putamen-auditory cortical connectivity with the neuropathological mechanism of AVH,providing evidence for the functional disconnection hypothesis of schizophrenia.
Cheng CHENGao-hua WANGShi-hao WUJi-lin ZOUYuan ZHOUHui-ling WANG
目的探讨抑郁症与精神分裂症患者脑功能活动及认知功能损害的特点及其相关性。方法对健康对照组、抑郁症组及精神分裂症组(每组各36例)患者进行数字符号测试(digital symbol test,DST)、数字广度测试(digital span test,DSPT)和语言流畅性测试(verbal fluency test,VFT),同时行静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)扫描,对rs-fMRI数据进行常规预处理,计算3组局部一致性(regional homogeneity,ReHo)及比率低频振幅(fractional amplitude of low frequency fluctuation,fALFF)值,分别比较3组认知功能测评及脑功能活动特点,采用Pearson相关分析认知功能与脑功能活动的相关性。结果(1)与健康对照组(68.75±10.40、9.22±1.07、5.95±1.67、22.39±4.53)比较,抑郁症组(60.86±10.75、8.06±0.80、5.19±1.12、19.36±2.85)与精神分裂症组(46.64±9.50、7.50±0.91、4.08±1.05、14.86±3.78)DST、DSPT顺背、DSPT倒背及VFT评分均下降,精神分裂症组较抑郁症组下降更显著(F=2.39、1.43、1.52、2.16,均P<0.01);(2)3组ReHo值存在差异的脑区为左侧豆状核-脑岛-罗兰岛盖(F=22.1,P<0.001,AlphaSim校正,体素个数>99),与健康对照组相比,抑郁症组在该脑区ReHo值升高,与抑郁症组相比,精神分裂症组在该脑区ReHo值降低。3组fALFF值存在差异的脑区为左侧顶上回及双侧脑岛-豆状核(F=28.46,13.12,P<0.001,AlphaSim校正,体素个数>90),与健康对照组和抑郁症组相比,精神分裂症组在左侧顶上回及双侧脑岛-豆状核的fALFF值均升高(P<0.05);(3)相关分析显示,抑郁症患者DST评分与左侧豆状核-脑岛-罗兰岛盖区ReHo值呈负相关(r=-0.38,P=0.02);精神分裂症患者DSPT倒背评分与脑岛-豆状核的fALFF值呈负相关(r=-0.39,P=0.02)。结论精神分裂症较抑郁症患者认知功能损害更为严重;抑郁症及精神分裂症患者顶叶、脑岛及纹状体活动异常,这些功能活动异常脑区可能是区分精神分裂症�
