Differential aberrant connectivity of precuneus and anterior insula may underpin the diagnosis of schizophrenia and mood disorders

BACKGROUND Over the past decade,resting-state functional magnetic resonance imaging(rsfMRI)has concentrated on brain networks such as the default mode network(DMN),the salience network(SN),and the central executive network(CEN),allowing for a better understanding of cognitive deficits observed in mental disorders,as well as other characteristic psychopathological phenomena such as thought and behavior disorganization.AIM To investigate differential patterns of effective connectivity across distributed brain networks involved in schizophrenia(SCH)and mood disorders.METHODS The sample comprised 58 patients with either paranoid syndrome in the context of SCH(n=26)or depressive syndrome(Ds)(n=32),in the context of major depressive disorder or bipolar disorder.The methods used include rs-fMRI and subsequent dynamic causal modeling to determine the direction and strength of connections to and from various nodes in the DMN,SN and CEN.RESULTS A significant excitatory connection from the dorsal anterior cingulate cortex to the anterior insula(aI)was observed in the SCH patient group,whereas inhibitory connections from the precuneus to the ventrolateral prefrontal cortex and from the aI to the precuneus were observed in the Ds group.CONCLUSION The results delineate specific patterns associated with SCH and Ds and offer a better explanation of the underlying mechanisms of these disorders,and inform differential diagnosis and precise treatment targeting.

Increased Local Spontaneous Neural Activity in the Left Precuneus Specific to Auditory Verbal Hallucinations of Schizophrenia

Background： Auditory verbal hallucinations （AVHs） of schizophrenia have been associated with structural and functional alterations of some brain regions. However, the brain regional homogeneity （ReHo） alterations specific to AVHs of schizophrenia remain unclear. In the current study, we aimed to investigate ReHo alterations specific to schizophrenic AVHs. Methods： Thirty-five schizophrenic patients with AVH, 41 schizophrenic patients without AVHs, and fifty healthy subjects underwent resting-state functional magnetic resonance imaging. ReHo differences across the three groups were tested using a voxel-wise analysis. Results： Compared with the healthy control group, the two schizophrenia groups showed significantly increased ReHo in the right caudate and inferior temporal gyrus and decreased ReHo in the bilateral postcentral gyrus and thalamus and the right inferior occipital gyrus （false discovery rate corrected, P 〈 0.05）. More importantly, the AVH group exhibited significantly increased ReHo in the left precuneus compared with the non-AVH group. However, using correlation analysis, we did not find any correlation between the auditory hallucination rating scale score and the ReHo of brain regions. Conclusions： Our results suggest that increased ReHo in the left precuneus may be a pathological feature exclusive to schizophrenic AVHs.

Increased functional connectivity of amygdala subregions in patients with drug-naïve panic disorder and without comorbidities

Background:Amygdala plays an important role in the neurobiological basis of panic disorder(PD),and the amygdala contains different subregions,which may play different roles in PD.The aim of the present study was to examine whether there are common or distinct patterns of functional connectivity of the amygdala subregions in PD using resting-state functional magnetic resonance imaging and to explore the relationship between the abnormal spontaneous functional connectivity patterns of the regions of interest(ROIs)and the clinical symptoms of PD patients.Methods:Fifty-three drug-naïve,non-comorbid PD patients and 70 healthy controls(HCs)were recruited.Seed-based resting-state functional connectivity(rsFC)analyses were conducted using the bilateral amygdalae and its subregions as the ROI seed.Two samples t test was performed for the seed-based Fisher's z-transformed correlation maps.The relationship between the abnormal spontaneous functional connectivity patterns of the ROIs and the clinical symptoms of PD patients was investigated by Pearson correlation analysis.Results:PD patients showed increased rsFC of the bilateral amygdalae and almost all the amygdala subregions with the precuneus/posterior cingulate gyrus compared with the HC group(left amygdala[lAMY]:t=4.84,P<0.001;right amygdala[rAMY]:t=4.55,P<0.001;left centromedial amygdala[lCMA]:t=3.87,P<0.001;right centromedial amygdala[rCMA]:t=3.82,P=0.002;left laterobasal amygdala[lBLA]:t=4.33,P<0.001;right laterobasal amygdala[rBLA]:t=4.97,P<0.001;left superficial amygdala[lSFA]:t=3.26,P=0.006).The rsFC of the lBLA with the left angular gyrus/inferior parietal lobule remarkably increased in the PD group(t=3.70,P=0.003).And most of the altered rsFCs were located in the default mode network(DMN).A significant positive correlation was observed between the severity of anxiety and the rsFC between the lSFA and the left precuneus in PD patients(r=0.285,P=0.039).Conclusions:Our research suggested that the increased rsFC of amygdala subregions with DMN plays an important role in the pathogenesis of PD.Future studies may further explore whether the rsFC of amygdala subregions,especially with the regions in DMN,can be used as a biological marker of PD.

散发性早发阿尔茨海默病中磷酸化tau蛋白的高负荷和特异性楔前叶萎缩:一项前瞻性队列研究

早发性阿尔茨海默病(EOAD)是阿尔茨海默病(AD)的罕见且严重的亚型,于65岁之前发病,占所有AD病例的5%~10%.以往关于EOAD的研究主要集中在家族性遗传人群,而对于占EOAD病例85%~90%的散发性EOAD(sEOAD)的研究则较为有限.在这项前瞻性队列研究中,共纳入sEOAD110例,晚发性AD(LOAD)89例,年龄匹配对照组75例.研究对象排除了家族性EOAD患者,所有纳入AD患者均符合基于ATN框架下的生物标志物证据的诊断标准.对纳入患者进行了患病危险因素分析、多维度认知功能评估、多模态分子影像学评估及脑脊液/外周血生物标记物检测.结果显示,与LOAD患者相比,sEOAD患者没有表现出特定的危险因素,但表现出更严重的执行功能损害和双侧楔前叶萎缩.在sEOAD患者中的脑脊液和血浆中磷酸化tau181(P-tau181)水平较LOAD组显著升高.本研究探讨了散发性EOAD人群的临床特征,发现了tau蛋白磷酸化在sEOAD发生和进展中的重要性,有助于全面了解AD的病因、发病年龄决定因素和疾病进展,并为潜在的治疗策略提供了重要思路.

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.