Effect of transcutaneous auricular vagus nerve stimulation on functional connectivity in the related brain regions of patients with depression based on the resting-state fMRI / 中国针灸

OBJECTIVE@#To explore the brain effect mechanism and the correlation between brain functional imaging and cognitive function in treatment of depressive disorder (DD) with transcutaneous auricular vagus nerve stimulation (taVNS) based on the resting-state functional magenetic reasonance imaging (rs-fMRI).@*METHODS@#Thirty-two DD patients were included in a depression group and 32 subjects of healthy condition were enrolled in a normal group. In the depression group, the taVNS was applied to bilateral Xin (CO15) and Shen (CO10), at disperse-dense wave, 4 Hz/20 Hz in frequency and current intensity ≤20 mA depending on patient's tolerance, 30 min each time, twice daily. The duration of treatment consisted of 8 weeks. The patients of two groups were undertaken rs-fMRI scanning. The scores of Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA) and Wisconsin card sorting test (WCST) were observed in the normal group at baseline and the depression group before and after treatment separately. The differential brain regions were observed before and after treatment in the two groups and the value of degree centrality (DC) of fMRI was obtained. Their correlation was analyzed in terms of HAMD, HAMA and WCST scores.@*RESULTS@#The scores of HAMD and HAMA in the depression group were all higher than those in the normal group (P<0.05). After treatment, the scores of HAMD and HAMA were lower than those before treatment in the depression group; the scores of total responses, response errors and perseverative errors of WCST were all lower than those before treatment (P<0.05). The brain regions with significant differences included the left inferior temporal gyrus, the left cerebellar peduncles region 1, the left insula, the right putamen, the bilateral supplementary motor area and the right middle frontal gyrus. After treatment, the value of DC in left supplementary motor area was negatively correlated to HAMD and HAMA scores respectively (r=-0.324, P=0.012; r=-0.310, P=0.015); the value of DC in left cerebellar peduncles region 1 was negatively correlated to the total responses of WCST (r=-0.322, P=0.013), and the left insula was positively correlated to the total responses of WCST (r=0.271, P=0.036).@*CONCLUSION@#The taVNS can modulate the intensity of the functional activities of some brain regions so as to relieve depressive symptoms and improve cognitive function.

Research progress on the interaction between myopia and visual cortex / 中华眼底病杂志

Myopia is a major problem of public health in China, and even in the world, and slowing down the progress of myopia has become a hot issue of concern. However, the effects of the current therapeutic and interventional modalities to myopia, including optical lenses, chemical drugs, and laser surgery, the effect of treatment and intervention is not very satisfactory, and these modalities may incur some side effects. This situation suggests that the pathogenic and regulatory mechanisms of myopia remain elusive, and the myopia treatments lack the accurate and effective targets to the etiology. A complete visual experience depends on the entire visual pathway from the retina to the visual cortex, in which any structural and functional defect can lead to visual abnormalities. In recent years, with the advances in the infrared spectroscopy and the magnetic resonance imaging technology, more and more evidence has shown that the progression of myopia is related to the visual cortex. Improving the functional connectivity and blood prefusion between different regions of the visual cortex may impede myopia profession. In-depth understanding of the interaction between myopia and the visual cortex is helpful to search for accurate and effective myopia treatment targets and novel intervention strategies.

Study on large-scale resting-state functional networks in first-episode untreated adult patients with major depressive disorder / 中华行为医学与脑科学杂志

Objective:To investigate the value of large-scale brain network research based on independent component analysis (ICA) in discovering the changes of intrinsic functional connections within and between resting-state networks (RSNs) in first-episode untreated adult patients with major depressive disorder (MDD).Methods:From January 2019 to June 2021, twenty-three patients with MDD (MDD group) and 30 healthy volunteers (HC group) matched with gender, age and years of education were selected. All participants underwent resting-state brain function imaging (rs-fMRI), and the MDD group completed the 17-item Hamilton depression scale(HAMD-17). The independent component analysis (ICA) method was used to analyze rs-fMRI data, and meaningful RSNs were obtained. SPM12 and Gift softwares were used to compare the strength of intrinsic functional connection within and between the RSNs of the MDD group and HC group, and the Pearson correlation analysis was conducted by IBM SPSS statistics 25.0 to evaluate the correlation between the functional connection strength and HAMD-17 scores in MDD group.Results:Compared with the HC group, intrinsic functional connection strength of medial prefrontal cortex (mPFC) (MNI: x, y, z=-6, 54, 25)in MDD group was significantly enhanced, while the intrinsic functional connection strength of the left angular gyrus (AG) (MNI: x, y, z=-48, -66, 21), the left precuneus (PCu) (MNI: x, y, z=-6, -63, 33), the left dorsolateral prefrontal cortex (dlPFC) (MNI: x, y, z=-36, 12, 51)and the right anterior insula (AI) (MNI: x, y, z=36, 21, 0)were significantly weakened. Compared with the HC group, functional connection strength between posterior default mode net work(pDMN) and anterior default mode network(aDMN) in MDD group was significantly weakened ( t=-2.206, P=0.032), and function connection strength between pDMN and left frontal parietal network(lFPN) was significantly strengthened ( t=2.318, P=0.025). In MDD group, intrinsic functional connection strength of mPFC and the functional connection strength of pDMN-lFPN were positively correlated with the HAMD-17 score ( r=0.524, P=0.010; r=0.441, P=0.035). Conclusion:Large-scale brain network study based on the ICA can find abnormal functional connections within and between RSNs in first-episode untreated adult patients with MDD, and provide objective imaging markers for the clinical diagnosis and treatment of MDD.

Abnormality of insular functional connectivity in uremic restless legs: A resting state functional magnetic resonance study / 西安交通大学学报(医学版)

Objective: To investigate the changes of insular functional connectivity in patients with uremic restless legs syndrome (uRLS) using seed-based resting-state functional connectivity analysis so as to explore the related risk factors for RLS. Methods: 3D high-resolution structural imaging was applied in 29 patients with uremic restless legs (uRLS group) and 29 healthy volunteers (control group) with maintenance hemodialysis. The greymatter volume of the insular cortex was assessed using a voxel-based morphometry (VBM) analysis and functional connectivity of insular variation was evaluated by a seed-based correlation analysis, while the seed was chosen as the significant difference of grey matter volume. Pearson correlation analysis was used to explore the significant correlation between functional connectivity and RLS score. The relationship between brain alterations and clinical variables were investigated with Logistic stepwise multiple regression analysis. Results: Compared with that in the control group, the area with reduced gray matter volume in the uRLS group was located on the left posterior insula (P<0.05, FWE correction). Taking the left post insular as a seed region, we further found reduced functional connectivity in patients mainly between the insular and primary sensorimotor cortex (S1), supplementary motor areas (SMA), and posterior mid-cingulate gyrus (P<0.05, FDR corrected). In uRLS group, the severity score of RLS was negatively correlated with insular-S1 functional connectivity (P<0.05, FDR corrected), while the hemoglobin level was negetively correlated with functional connectivity degree of insular-S1 (r=-0.449, P=0.015, FDR corrected). Conclusion: The altered morphology of the post insular cortex was revealed in uRLS patients. Abnormal sensorimotor activities in patients with RLS were closely associated with reduced functional connectivity of insular-S1. Low hemoglobin level was the most important risk factor for the abnormal functional connectivity of the brain.

Resting-state functional magnetic resonance imaging of supramarginal gyrus-cerebellum circuit in obsessive-compulsive disorder / 中华行为医学与脑科学杂志

Objective Regional homogeneity (ReHo) and functional connectivity (FC) were used to study obsessive-compulsive disorder(OCD),and to explore the mechanism of OCD in resting state.Method Resting-state functional magnetic resonance imaging (RS-fMRI) was performed in 55 patients with OCD (OCD group) and 50 normal controls (control group) matched by sex,age,nationality and education.The data and screening abnormal brain areas were analyzed and compared by DPARSFA2.3 and Rest software in OCD group.Whole brain FC analysis was performed with abnormal brain areas as seed points.Result Compared with the control group,ReHo in right thalamus (MNI:x=9,y=-24,z=6,t=4.3217) and left superior marginal gyrus (MNI:x =-45,y =-30,z =27,t =3.6320) increased and ReHo in right caudate nucleus (MNI:x=3,y=15,z=9,t=-3.1687) decreased in obsessive-compulsive disorder group,and the difference was statistically significant(P＜0.05).Using left superior marginal gyrus,fight thalamus and right caudate nucleus as seed voxels,the whole brain FC analysis showed that there were abnormal functional connections between bilateral cerebellar foot 1/2 area and left supramarginal gyrus,right thalamus and right caudate nucleus (P＜0.05) and the left supramarginal gyrus-bilateral cerebellum feet 1 area-right thalamic circuit and left supramarginal gyrus-bilateral cerebellum feet 1,2-right caudate nucleus-right thalamic circuit existed in 0CD group.Conclusion The left supramarginal gyrus-bilateral cerebellum feet 1 area-right thalamic circuit and left supramarginal gyrus-bilateral cerebellum feet 1,2-right caudate nucleus-right thalamic circuit may play an important role in the mechanism of OCD.

Hybrid PET/MR analysis of neural mechanism for default mode network / 中国医学影像技术

Objective To investigate the relationship between spatial distribution of default mode network and glucose uptake.Methods Nine healthy subjects were scanned with hybrid PET/MR.Resting state MRI (rs-fMRI) and PET data were obtained.Spatial distribution analysis was performed between default mode network and glucose uptake.The relationship between the functional connectivity of default mode network and the distribution of glucose uptake were further analyzed.Results The similar spatial distribution pattern was found between default mode network and glucose uptake.Correlation between functional connectivity and glucose uptake in the default mode network showed that the best correlation coefficient between the values of functional connectivity and relative glucose uptake (rGU) was achieved in the right posterior cingulate cortex (rs =0.833,P＜0.001).Conclusion Hybrid PET/MR is very important to investigate neural mechanism of default mode network.

Change of Whole Brain Degree in Primary Insomnia / 中山大学学报(医学科学版)

[Objective] Based on the resting state functional magnetic resonance imaging to investigate the abnormal features of the functional connectivity of resting brain neural network in the patients with primary insomnia,by using voxel-wise whole-brain finctional networks analysis of degree centrality (DC) for imaging evidence of neural mechanisms underlying primary insomnia.[Methods] The resting state fMRI were performed in 59 PI patients and 47 age,education,and sex-matched normal healthy subjects.Analysis of DC map changes between the two patient groups and the control group were performed by two sample t test.(threshold at P ＜ 0.05).[Results] Compared with the control group,the patients with PI showed significantly reduced DC value in bilateral medial frontal gyrus (MFG),bilateral anterior cingulate gyrus (ACG),and right insula;and increased DC value in right middle temporal gyrus (MTG),and left cuneus,(CUN),P ＜ 0.05.[Conclusion]Changes of DC value occurred in some region of brain in the P[patient groups when compared with the control group.It was indicated that DC,as a novel resting-state fMRI parameter in the voxel-wise whole-brain functional networks,might be an appealing alternative approach for further study on pathologic and neuropsychological states of PI.

Preliminary exploration of the frontal-cingulate functional connection during identifying sad facial expression in depressed patients / 中华行为医学与脑科学杂志

Objective To analyze the difference of frontal-cingulate functional connection between patients with major depression and healthy controls in recognization of sad facial expression, and discuss the neutral basis of emotional bias in preliminary. Methods 12 female patients with major depression and 12 matched healthy controls were scanned. The intensities of brain activation in the process of sad and neutral facial expression recognition were analyzed, and the strengths of frontal-cingulate functional connection were compared between the two groups based on dynamic causal modeling. Results Comparing the stimulus adjusting connection models with Bayesian model indicated that model Ⅱ matched with the observation data better. In the comparison between model Ⅱ and model I ,the average Bayes factor was more than 7.38. In the comparison between model Ⅱ and model Ⅲ,the average Bayes factor was more than 2.71. Calculating the intrinsic connection parameters and stimulus adjusting connection parameters based on intrinsic connection model and stimulus adjusting connection model( model Ⅱ ), the result showed that connection strength between anterior cingulate and right inferior frontal gyrus in depression was greater than that in healthy controls. Conclusion The frontal-cingulate functional connection of patients with major depression is increased abnormally ,which may be the neural basis of negative emotional bias.

The Brain Mechanism of Developmental Dyslexia:Evidences From The Brain Image / 生物化学与生物物理进展

Developmental dyslexia is a specific learning disability. The cerebral mechanism of development dyslexia is an important topic that has fascinated many researchers. With the introduction of brain imaging in studies of cerebral mechanism of development dyslexia, many achievements have been made. Studies of developmental dyslexia structure image found that development dyslexia showed brain structure abnormal in the parietotemporal region, occipitotemporal cortex, inferior frontal gyrus, and cerebellum et al, manifesting either in one specific area or by the asymmetry of one area; the functional image studies revealed that development dyslexia showed activity abnormal in most regions that proved to display structure abnormality; studies of brain functional connectivity demonstrates that the abnormality of development dyslexia happened not only in the connection between front-back part in one cerebral hemisphere, but also in the connection between the two hemispheres. In addition, some studies indicate Chinese development dyslexia has different brain mechanisms compared to that of alphabetic languages. These findings provide valuable insight for future developmental cerebral mechanisms research and for the expansion of Chinese development dyslexia research.