New resting-state fMRI related studies at PubMed

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Dynamic functional connectivity in schizophrenia and autism spectrum disorder: Convergence, divergence and classification.

Mon, 08/12/2019 - 13:00
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Dynamic functional connectivity in schizophrenia and autism spectrum disorder: Convergence, divergence and classification.

Neuroimage Clin. 2019 Aug 01;24:101966

Authors: Rabany L, Brocke S, Calhoun VD, Pittman B, Corbera S, Wexler BE, Bell MD, Pelphrey K, Pearlson GD, Assaf M

Abstract
BACKGROUND: Over the recent years there has been a growing debate regarding the extent and nature of the overlap in neuropathology between schizophrenia (SZ) and autism spectrum disorder (ASD). Dynamic functional network connectivity (dFNC) is a recent analysis method that explores temporal patterns of functional connectivity (FC). We compared resting-state dFNC in SZ, ASD and healthy controls (HC), characterized the associations between temporal patterns and symptoms, and performed a three-way classification analysis based on dFNC indices.
METHODS: Resting-state fMRI was collected from 100 young adults: 33 SZ, 33 ASD, 34 HC. Independent component analysis (ICA) was performed, followed by dFNC analysis (window = 33 s, step = 1TR, k-means clustering). Temporal patterns were compared between groups, correlated with symptoms, and classified via cross-validated three-way discriminant analysis.
RESULTS: Both clinical groups displayed an increased fraction of time (FT) spent in a state of weak, intra-network connectivity [p < .001] and decreased FT in a highly-connected state [p < .001]. SZ further showed decreased number of transitions between states [p < .001], decreased FT in a widely-connected state [p < .001], increased dwell time (DT) in the weakly-connected state [p < .001], and decreased DT in the highly-connected state [p = .001]. Social behavior scores correlated with DT in the widely-connected state in SZ [r = 0.416, p = .043], but not ASD. Classification correctly identified SZ at high rates (81.8%), while ASD and HC at lower rates.
CONCLUSIONS: Results indicate a severe and pervasive pattern of temporal aberrations in SZ (specifically, being "stuck" in a state of weak connectivity), that distinguishes SZ participants from both ASD and HC, and is associated with clinical symptoms.

PMID: 31401405 [PubMed - as supplied by publisher]

Altered spontaneous activity and functional connectivity in the posterior pons of patients with migraine without aura.

Sun, 08/11/2019 - 12:00
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Altered spontaneous activity and functional connectivity in the posterior pons of patients with migraine without aura.

J Pain. 2019 Aug 07;:

Authors: Qin Z, He XW, Zhang J, Xu S, Li GF, Su J, Shi YH, Ban S, Hu Y, Liu YS, Zhuang MT, Zhao R, Shen XL, Li J, Liu JR, Du X

Abstract
The brainstem has been discussed as the main player in the pathogenesis of migraine. Dysfunctional brainstem nuclei and their abnormal connections to other key brain centers may contribute to headache and other symptoms of migraine. In the present study, 32 patients with migraine without aura (MWoA) and 32 age- and sex-matched healthy controls (HCs) underwent resting-state fMRI scans. We used masked independent analysis (mICA) to investigate whether patients with MWoA exhibited abnormal brainstem nuclei-cortical functional connectivity (FC). The mICA can suppress adjacent physiological noise and prevent results from being driven by the much stronger signals of the surrounding structures. Regional homogeneity (ReHo) was used to investigate whether the brainstem regions with abnormal FC to other brain areas exhibited abnormal regional neuronal activity. Patients with MWoA showed significantly weaker FC between the posterior pons and the left superior parietal lobule, the left middle temporal gyrus and the left middle frontal gyrus. Furthermore, patients with MWoA exhibited significantly decreased ReHo values in the posterior pons compared with HCs, and the posterior pons ReHo value was significantly negatively correlated with HIT-6 scores in the MWoA group. Patients with MWoA exhibited functional abnormalities in the posterior pons and weakened connections between the posterior pons and several key cortical brain areas involved in pain processing during the resting state. Perspective: This study provided increased evidence that the pons is involved in pathophysiological mechanism of migraine, and weakened connections suggest that the touch and pain sensation of migraine sufferers may not be properly relayed to cortical processing areas, which may be associated with the pathogenesis of MWoA.

PMID: 31400473 [PubMed - as supplied by publisher]

Functional Connectivity of the Striatum in Schizophrenia and Psychotic Bipolar Disorder.

Sun, 08/11/2019 - 12:00
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Functional Connectivity of the Striatum in Schizophrenia and Psychotic Bipolar Disorder.

Biol Psychiatry Cogn Neurosci Neuroimaging. 2019 Jun 12;:

Authors: Karcher NR, Rogers BP, Woodward ND

Abstract
BACKGROUND: The striatum is abnormal in schizophrenia and possibly represents a common neurobiological mechanism underlying psychotic disorders. Resting-state functional magnetic resonance imaging studies have not reached a consensus regarding striatal dysconnectivity in schizophrenia, although these studies generally find impaired frontoparietal and salience network connectivity. The goal of the current study was to clarify the pattern of corticostriatal connectivity, including whether corticostriatal dysconnectivity is transdiagnostic and extends into psychotic bipolar disorder.
METHODS: We examined corticostriatal functional connectivity in 60 healthy subjects and 117 individuals with psychosis, including 77 with a schizophrenia spectrum illness and 40 with psychotic bipolar disorder. We conducted a cortical seed-based region-of-interest analysis with follow-up voxelwise analysis for any significant results. Further, a striatum seed-based analysis was conducted to examine group differences in connectivity between the striatum and the whole cortex.
RESULTS: Cortical region-of-interest analysis indicated that overall connectivity of the salience network with the striatum was reduced in psychotic disorders, which follow-up voxelwise analysis localized to the left putamen. Striatum seed-based analyses showed reduced ventral rostral putamen connectivity with the salience network portion of the medial prefrontal cortex in both schizophrenia and psychotic bipolar disorder.
CONCLUSIONS: The current study found evidence of transdiagnostic corticostriatal dysconnectivity in both schizophrenia and psychotic bipolar disorder, including reduced salience network connectivity, as well as reduced connectivity between the putamen and the medial prefrontal cortex. Overall, the current study points to the relative importance of salience network hypoconnectivity in psychotic disorders.

PMID: 31399394 [PubMed - as supplied by publisher]

Comparison of intrinsic brain activity in individuals with low/moderate myopia versus high myopia revealed by the amplitude of low-frequency fluctuations.

Sun, 08/11/2019 - 12:00
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Comparison of intrinsic brain activity in individuals with low/moderate myopia versus high myopia revealed by the amplitude of low-frequency fluctuations.

Acta Radiol. 2019 Aug 09;:284185119867633

Authors: Cheng Y, Huang X, Hu YX, Huang MH, Yang B, Zhou FQ, Wu XR

PMID: 31398992 [PubMed - as supplied by publisher]

Thoughts of death affect reward learning by modulating salience network activity.

Sat, 08/10/2019 - 10:40

Thoughts of death affect reward learning by modulating salience network activity.

Neuroimage. 2019 Aug 06;:116068

Authors: Luo S, Wu B, Fan X, Yiyi Z, Wu X, Han S

Abstract
Thoughts of death substantially influence human behavior and psychological well-being. A large number of behavioral studies have shown evidence that asking individuals to think about death or mortality salience leads to significant changes of their behaviors. These findings support the well-known terror management theory to account for the psychological mechanisms of existential anxiety. However, despite increasing findings of mortality salience effects on human behavior, how the brain responds to reminders of mortality and changes the activity underlying subsequent behavior remains poorly understood. By scanning healthy adults (N = 80) of both sexes using functional magnetic resonance imaging, we showed that, relative to reading emotionally neutral sentences, reading sentences that evoke death-related thoughts decreased the salience network activity, reduced the connectivity between the cingulate cortex and other brain regions during a subsequent resting state, and dampened the speed of learning reward-related objects and cingulate responses to loss feedback during a subsequent reward learning task. In addition, the decreased resting-state cingulate connectivity mediated the association between salience network deactivations in response to reminders of mortality and suppressed cingulate responses to loss feedback. Finally, the suppressed cingulate responses to loss feedback further predicted the dampened speed of reward learning. Our findings demonstrate sequential modulations of the salience network activity by mortality salience, which provide a neural basis for understanding human behavior under mortality threat.

PMID: 31398436 [PubMed - as supplied by publisher]

Stress and the brain: Perceived stress mediates the impact of the superior frontal gyrus spontaneous activity on depressive symptoms in late adolescence.

Sat, 08/10/2019 - 10:40

Stress and the brain: Perceived stress mediates the impact of the superior frontal gyrus spontaneous activity on depressive symptoms in late adolescence.

Hum Brain Mapp. 2019 Aug 09;:

Authors: Wang S, Zhao Y, Zhang L, Wang X, Wang X, Cheng B, Luo K, Gong Q

Abstract
Identifying factors for the prediction of depression is a long-standing research topic in psychiatry and psychology. Perceived stress, which reflects the tendency to appraise one's life situations as stressful and overwhelming, has emerged as a stable predictor for depressive symptoms. However, the neurobiological bases of perceived stress and how perceived stress influences depressive symptoms in the healthy brain remain largely unknown. Here, we investigated these issues in 217 healthy adolescents by estimating the fractional amplitude of low-frequency fluctuations (fALFFs) via resting-state functional magnetic resonance imaging. A whole-brain correlation analysis showed that higher levels of perceived stress were associated with greater fALFF in the left superior frontal gyrus (SFG), which is a core brain region for cognitive control and emotion regulation-related processes. Mediation analysis further indicated that perceived stress mediated the link between the fALFF in the left SFG and depressive symptoms. Importantly, our results remained significant even when excluding the influences of head motion, anxiety, SFG gray matter structure, and school environment. Altogether, our findings suggested that the fALFF in the left SFG is a neurofunctional marker of perceived stress in adolescents and revealed a potential indirect effect of perceived stress on the association between the SFG spontaneous activity and depressive symptoms.

PMID: 31397949 [PubMed - as supplied by publisher]

Modulatory effect of International Standard Scalp Acupuncture on brain activation in the elderly as revealed by resting-state fMRI.

Sat, 08/10/2019 - 10:40

Modulatory effect of International Standard Scalp Acupuncture on brain activation in the elderly as revealed by resting-state fMRI.

Neural Regen Res. 2019 Dec;14(12):2126-2131

Authors: Chung WY, Liu SY, Gao JC, Jiang YJ, Zhang J, Qu SS, Zhang JP, Tan XL, Chen JQ, Wang SX

Abstract
The specific mechanisms by which acupuncture affects the central nervous system are unclear. In the International Standard Scalp Acupuncture system, acupuncture needles are applied at the middle line of the vertex, anterior parietal-temporal oblique line, and the posterior parietal-temporal oblique line. We conducted a single-arm prospective clinical trial in which seven healthy elderly volunteers (three men and four women; 50-70 years old) received International Standard Scalp Acupuncture at MS5 (the mid-sagittal line between Baihui (DU20) and Qianding (DU21)), the left MS6 (line joining Sishencong (EX-HN1) and Xuanli (GB6)), and the left MS7 (line joining DU20 and Qubin (GB7)). After acupuncture, resting-state functional magnetic resonance imaging demonstrated changes in the fractional amplitude of low frequency fluctuations and regional homogeneity in various areas, showing remarkable enhancement of regional homogeneity in the bilateral anterior cingulate, left medial frontal gyrus, supramarginal gyrus, right middle frontal gyrus, and inferior frontal gyrus. Functional connectivity based on a seed region at the right middle frontal gyrus (42, 51, 9) decreased at the bilateral medial superior frontal gyrus. Our data preliminarily indicates that the international standard scalp acupuncture in healthy elderly participants specifcally enhances the correlation between the brain regions involved in cognition and implementation of the brain network regulation system and the surrounding adjacent brain regions. The study was approved by the Ethics Committee of the China-Japan Union Hospital at Jilin University, China, on July 18, 2016 (approval No. 2016ks043).

PMID: 31397351 [PubMed]

Altered Functional Connectivity Between the Cerebellum and the Cortico-Striato-Thalamo-Cortical Circuit in Obsessive-Compulsive Disorder.

Sat, 08/10/2019 - 10:40
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Altered Functional Connectivity Between the Cerebellum and the Cortico-Striato-Thalamo-Cortical Circuit in Obsessive-Compulsive Disorder.

Front Psychiatry. 2019;10:522

Authors: Zhang H, Wang B, Li K, Wang X, Li X, Zhu J, Zhao Q, Yang Y, Lv L, Zhang M, Zhang H

Abstract
Background: Altered resting-state functional connectivity of the cerebellum in obsessive-compulsive disorder (OCD) has been previously reported. However, the previous study investigating cerebellar-cerebral functional connectivity relied on a priori-defined seeds from specific networks. In this study, we aimed to explore the connectivity alterations of the cerebellum in OCD under resting-state conditions with a hypothesis-free approach. Methods: Thirty patients with OCD and 26 healthy controls (HCs) underwent functional magnetic resonance imaging (fMRI) scanning at resting state. Regional cerebral function was evaluated by measuring the fraction of amplitude of low-frequency fluctuation (fALFF). Regions with mean fALFF (mfALFF) alterations were used as seeds in seed correlation analysis (SCA). An independent samples t test was used to compare the differences in mfALFF and functional connection (FC) between the two groups. Pearson correlation analysis was performed to identify the association between functional neural correlates and OCD symptom severity evaluated using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Results: Compared with the HC group, the OCD group showed significantly increased mfALFF values in bilateral cerebellar. The results of FC analysis showed weakened connectivity among the left Crus II, lobule VIII, and right striatum and between the right lobule VIII and the right striatum, and cingulate in the OCD group compared with the HC group. Some of the abovementioned results were associated with symptom severity. Conclusions: OCD patients showed abnormal spontaneous cerebellar activity and weakened functional connectivity between the cerebellum and the cortico-striato-thalamo-cortical (CSTC) circuit (striatum and cingulate), suggesting that the cerebellum may play an essential role in the pathophysiology of OCD.

PMID: 31396115 [PubMed]

Functional Brain Changes During Mindfulness-Based Cognitive Therapy Associated With Tinnitus Severity.

Sat, 08/10/2019 - 10:40
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Functional Brain Changes During Mindfulness-Based Cognitive Therapy Associated With Tinnitus Severity.

Front Neurosci. 2019;13:747

Authors: Zimmerman B, Finnegan M, Paul S, Schmidt S, Tai Y, Roth K, Chen Y, Husain FT

Abstract
Mindfulness-based therapies have been introduced as a treatment option to reduce the psychological severity of tinnitus, a currently incurable chronic condition. This pilot study of twelve subjects with chronic tinnitus investigates the relationship between measures of both task-based and resting state functional magnetic resonance imaging (fMRI) and measures of tinnitus severity, assessed with the Tinnitus Functional Index (TFI). MRI was measured at three time points: before, after, and at follow-up of an 8-week long mindfulness-based cognitive therapy intervention. During the task-based fMRI with affective sounds, no significant changes were observed between sessions, nor was the activation to emotionally salient compared to neutral stimuli significantly predictive of TFI. Significant results were found using resting state fMRI. There were significant decreases in functional connectivity among the default mode network, cingulo-opercular network, and amygdala across the intervention, but no differences were seen in connectivity with seeds in the dorsal attention network (DAN) or fronto-parietal network and the rest of the brain. Further, only resting state connectivity between the brain and the amygdala, DAN, and fronto-parietal network significantly predicted TFI. These results point to a mostly differentiated landscape of functional brain measures related to tinnitus severity on one hand and mindfulness-based therapy on the other. However, overlapping results of decreased amygdala connectivity with parietal areas and the negative correlation between amygdala-parietal connectivity and TFI is suggestive of a brain imaging marker of successful treatment.

PMID: 31396035 [PubMed]

Disrupted Regional Cerebral Blood Flow, Functional Activity and Connectivity in Alzheimer's Disease: A Combined ASL Perfusion and Resting State fMRI Study.

Sat, 08/10/2019 - 10:40
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Disrupted Regional Cerebral Blood Flow, Functional Activity and Connectivity in Alzheimer's Disease: A Combined ASL Perfusion and Resting State fMRI Study.

Front Neurosci. 2019;13:738

Authors: Zheng W, Cui B, Han Y, Song H, Li K, He Y, Wang Z

Abstract
Recent studies have demonstrated a close relationship between regional cerebral blood flow (rCBF) and resting state functional connectivity changes in normal healthy people. However, little is known about the parameter changes in the most vulnerable regions in Alzheimer's disease (AD). Forty AD patients and 30 healthy controls participated in this study. The data of resting-state perfusion and functional magnetic resonance imaging (fMRI) was collected. By using voxel-wise arterial spin labeling (ASL) perfusion, we identified several regions of altered rCBF in AD patients. Then, by using resting state fMRI analysis, including amplitude low frequency fluctuation (ALFF) and seed-based functional connectivity, we investigated the changes of functional activity and connectivity among the identified rCBF regions. We extracted cognition-related parameters and searched for a sensitive biomarker to differentiate the AD patients from the normal controls (NC). Compared with controls, AD patients showed special disruptions in rCBF, which were mainly located in the left posterior cingulate cortex (PCC), the left and right dorsolateral prefrontal cortex (DLPFC), the left inferior parietal lobule (IPL), the right middle temporal gyrus (MTG), the left middle occipital gyrus (MOG), and the left precuneus (PCu). ALFF was performed based on the seven regions identified by the ASL method, and AD patients presented significantly decreased ALFF in the left PCC, left IPL, right MTG, left MOG, and left PCu and increased ALFF in the bilateral DLPFC. We constituted the network based on the seven regions and found that there was decreased connectivity among the identified regions in the AD patients, which predicted a disruption in the default mode network (DMN), executive control network (ECN) and visual network (VN). Furthermore, these abnormal parameters are closely associated with cognitive performances in AD patients. We combined the rCBF and ALFF value of PCC/PCu as a biomarker to differentiate the two groups and reached a sensitivity of 85.3% and a specificity of 88.5%. Our findings suggested that there was disrupted rCBF, functional activity and connectivity in specific cognition-related regions in Alzheimer's disease, which can be used as a valuable imaging biomarker for the diagnosis of AD.

PMID: 31396033 [PubMed]

Spatiotemporal Empirical Mode Decomposition of Resting-State fMRI Signals: Application to Global Signal Regression.

Sat, 08/10/2019 - 10:40
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Spatiotemporal Empirical Mode Decomposition of Resting-State fMRI Signals: Application to Global Signal Regression.

Front Neurosci. 2019;13:736

Authors: Moradi N, Dousty M, Sotero RC

Abstract
Resting-state functional connectivity MRI (rs-fcMRI) is a common method for mapping functional brain networks. However, estimation of these networks is affected by the presence of a common global systemic noise, or global signal (GS). Previous studies have shown that the common preprocessing steps of removing the GS may create spurious correlations between brain regions. In this paper, we decompose fMRI signals into 5 spatial and 3 temporal intrinsic mode functions (SIMF and TIMF, respectively) by means of the empirical mode decomposition (EMD), which is an adaptive data-driven method widely used to analyze non-linear and non-stationary phenomena. For each SIMF, functional connectivity matrices were computed by means of Pearson correlation between TIMFs of different brain areas. Thus, instead of a single connectivity matrix, we obtained 5 × 3 = 15 functional connectivity matrices. Given the high correlation and global efficiency values of the connectivity matrices related to the low spatial maps (SIMF3, SIMF4, and SIMF5), our results suggest that these maps can be considered as spatial global signal masks. Thus, by summing up the first two SIMFs extracted from the fMRI signals, we have automatically excluded the GS which is now voxel-specific. We compared the performance of our method with the conventional GS regression and to the results when the GS was not removed. While the correlation pattern identified by the other methods suffers from a low level of precision in identifying the correct brain network connectivity, our approach demonstrated expected connectivity patterns for the default mode network and task-positive network.

PMID: 31396032 [PubMed]

Modulatory effects of different exercise modalities on the functional connectivity of the periaqueductal grey and ventral tegmental area in patients with knee osteoarthritis: a randomised multimodal magnetic resonance imaging study.

Sat, 08/10/2019 - 10:40
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Modulatory effects of different exercise modalities on the functional connectivity of the periaqueductal grey and ventral tegmental area in patients with knee osteoarthritis: a randomised multimodal magnetic resonance imaging study.

Br J Anaesth. 2019 Aug 05;:

Authors: Liu J, Chen L, Chen X, Hu K, Tu Y, Lin M, Huang J, Liu W, Wu J, Qiu Z, Zhu J, Li M, Park J, Wilson G, Lang C, Xie G, Tao J, Kong J

Abstract
BACKGROUND: Knee osteoarthritis is a prevalent disorder with unsatisfactory treatment options. Both physical and mindful exercises may be able to relieve its pain symptoms. We compared the modulatory effects of different exercise modalities on the periaqueductal grey (PAG) and ventral tegmental area (VTA), which play important roles in descending opioidergic pathways and reward/motivation systems in patients with knee osteoarthritis.
METHODS: We recruited and randomised 140 patients into Tai Chi, Baduanjin, stationary cycling, and health education control groups for 12 weeks. Knee injury and Osteoarthritis Outcome Score (KOOS), functional and structural MRI, and blood biomarkers were measured at the beginning and end of the experiment. We used the PAG and VTA as seeds in resting-state functional connectivity (rsFC) analysis.
RESULTS: Compared with the control group: (i) all exercises significantly increased KOOS pain sub-scores (pain reduction) and serum programmed death 1 (PD-1) concentrations as well as decreased serum interferon gamma concentrations; (ii) all exercises decreased right PAG rsFC with the medial orbital prefrontal cortex, and the decreased rsFC was associated with improvements in knee pain; and (iii) grey matter volume in the medial orbital prefrontal cortex was significantly increased in all exercise groups. There was also significantly decreased rsFC between the left VTA and the medial orbital prefrontal cortex in the Tai Chi and Baduanjin groups.
CONCLUSIONS: Exercise can simultaneously modulate the rsFC of the descending opioidergic pathway and reward/motivation system and blood inflammation markers. Elucidating the shared and unique mechanisms of different exercise modalities may facilitate the development of exercise-based interventions for chronic pain.
CLINICAL TRIAL REGISTRATION: ChiCTR-IOR-16009308.

PMID: 31395306 [PubMed - as supplied by publisher]

Distinct Dynamic Functional Connectivity Patterns of Pain and Touch Thresholds: A Resting-state fMRI Study.

Fri, 08/09/2019 - 15:40
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Distinct Dynamic Functional Connectivity Patterns of Pain and Touch Thresholds: A Resting-state fMRI Study.

Behav Brain Res. 2019 Aug 05;:112142

Authors: Yuan Y, Zhang L, Li L, Huang G, Anter A, Liang Z, Zhang Z

Abstract
Dynamic functional connectivity (dFC) analysis based on resting-state functional magnetic resonance imaging (fMRI) has gained popularity in recent years. Despite many studies have linked dFC patterns to various mental diseases and cognitive functions, little research has used dFC in the investigation of low-level sensory perception. The present study is aimed to explore resting-state fMRI dFC patterns correlated with thresholds of two types of perception, pain and touch, on an individual basis. We collected and analyzed resting-state fMRI data and thresholds of pain and touch from 80 healthy participants. dFC states were identified by using independent component analysis, sliding window correlation, and clustering, and then the thresholds of pain and touch are correlated with the occurrence frequencies of dFC states. A new permutation analysis is developed to make identified dFC states more interpretable. We found that the occurrence frequency of a default mode network (DMN)-dominated state was positively correlated with the pain threshold, while the occurrence frequency of a static functional connectivity (sFC)-like state was negatively correlated with the touch threshold. This study showed that the thresholds of pain and touch have distinct dFC correlates, suggesting different influences of baseline brain states on different types of sensory perception. This study also showed that dFC could serve as an indicator of an individual's pain sensitivity, which can be potentially used for pain management.

PMID: 31394144 [PubMed - as supplied by publisher]

Association between dynamic resting-state functional connectivity and ketamine plasma levels in visual processing networks.

Fri, 08/09/2019 - 15:40
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Association between dynamic resting-state functional connectivity and ketamine plasma levels in visual processing networks.

Sci Rep. 2019 Aug 07;9(1):11484

Authors: Spies M, Klöbl M, Höflich A, Hummer A, Vanicek T, Michenthaler P, Kranz GS, Hahn A, Winkler D, Windischberger C, Kasper S, Lanzenberger R

Abstract
Numerous studies demonstrate ketamine's influence on resting-state functional connectivity (rsFC). Seed-based and static rsFC estimation methods may oversimplify FC. These limitations can be addressed with whole-brain, dynamic rsFC estimation methods. We assessed data from 27 healthy subjects who underwent two 3 T resting-state fMRI scans, once under subanesthetic, intravenous esketamine and once under placebo, in a randomized, cross-over manner. We aimed to isolate only highly robust effects of esketamine on dynamic rsFC by using eight complementary methodologies derived from two dynamic rsFC estimation methods, two functionally defined atlases and two statistical measures. All combinations revealed a negative influence of esketamine on dynamic rsFC within the left visual network and inter-hemispherically between visual networks (p < 0.05, corrected), hereby suggesting that esketamine's influence on dynamic rsFC is highly stable in visual processing networks. Our findings may be reflective of ketamine's role as a model for psychosis, a disorder associated with alterations to visual processing and impaired inter-hemispheric connectivity. Ketamine is a highly effective antidepressant and studies have shown changes to sensory processing in depression. Dynamic rsFC in sensory processing networks might be a promising target for future investigations of ketamine's antidepressant properties. Mechanistically, sensitivity of visual networks for esketamine's effects may result from their high expression of NMDA-receptors.

PMID: 31391479 [PubMed - in process]

Detecting schizophrenia at the level of the individual: relative diagnostic value of whole-brain images, connectome-wide functional connectivity and graph-based metrics.

Fri, 08/09/2019 - 15:40
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Detecting schizophrenia at the level of the individual: relative diagnostic value of whole-brain images, connectome-wide functional connectivity and graph-based metrics.

Psychol Med. 2019 Aug 08;:1-10

Authors: Lei D, Pinaya WHL, van Amelsvoort T, Marcelis M, Donohoe G, Mothersill DO, Corvin A, Gill M, Vieira S, Huang X, Lui S, Scarpazza C, Young J, Arango C, Bullmore E, Qiyong G, McGuire P, Mechelli A

Abstract
BACKGROUND: Previous studies using resting-state functional neuroimaging have revealed alterations in whole-brain images, connectome-wide functional connectivity and graph-based metrics in groups of patients with schizophrenia relative to groups of healthy controls. However, it is unclear which of these measures best captures the neural correlates of this disorder at the level of the individual patient.
METHODS: Here we investigated the relative diagnostic value of these measures. A total of 295 patients with schizophrenia and 452 healthy controls were investigated using resting-state functional Magnetic Resonance Imaging at five research centres. Connectome-wide functional networks were constructed by thresholding correlation matrices of 90 brain regions, and their topological properties were analyzed using graph theory-based methods. Single-subject classification was performed using three machine learning (ML) approaches associated with varying degrees of complexity and abstraction, namely logistic regression, support vector machine and deep learning technology.
RESULTS: Connectome-wide functional connectivity allowed single-subject classification of patients and controls with higher accuracy (average: 81%) than both whole-brain images (average: 53%) and graph-based metrics (average: 69%). Classification based on connectome-wide functional connectivity was driven by a distributed bilateral network including the thalamus and temporal regions.
CONCLUSION: These results were replicated across the three employed ML approaches. Connectome-wide functional connectivity permits differentiation of patients with schizophrenia from healthy controls at single-subject level with greater accuracy; this pattern of results is consistent with the 'dysconnectivity hypothesis' of schizophrenia, which states that the neural basis of the disorder is best understood in terms of system-level functional connectivity alterations.

PMID: 31391132 [PubMed - as supplied by publisher]

Functional connectivity of reflective and brooding rumination in depressed and healthy women.

Fri, 08/09/2019 - 15:40
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Functional connectivity of reflective and brooding rumination in depressed and healthy women.

Cogn Affect Behav Neurosci. 2018 10;18(5):884-901

Authors: Satyshur MD, Layden EA, Gowins JR, Buchanan A, Gollan JK

Abstract
Ruminative thinking is related to an increased risk for major depressive disorder (MDD) and perpetuates negative mood states. Rumination, uncontrollable negative thoughts about the self, may comprise both reflective and brooding components. However, only brooding rumination is consistently associated with increased negativity bias and negative coping styles, while reflective rumination has a less clear relationship with negative outcomes in healthy and depressed participants. The current study examined seed-to-voxel (S2.V) resting-state functional connectivity (FC) in a sample of healthy (HC) and depressed (MDD) adult women (HC: n=50, MDD: n=33). The S2V FC of six key brain regions, including the left and right amygdala, anterior and posterior cingulate cortex (ACC, PCC), and medial and dorsolateral prefrontal cortices (mPFC, dlPFC), was correlated with self-reported reflective and brooding rumination. Results indicate that HC and MDD participants had increased brooding rumination associated with decreased FC between the left amygdala and the right temporal pole. Moreover, reflective rumination was associated with distinct FC of the mPFC, PCC, and ACC with parietal, occipital, and cingulate regions. Depressed participants, compared with HC, exhibited decreased FC between the PCC and a region in the right middle frontal gyrus. The results of the current study add to the understanding of the neural underpinnings of different forms of self-related cognition-brooding and reflective rumination-in healthy and depressed women.

PMID: 29949111 [PubMed - indexed for MEDLINE]

Neuroimaging adolescents with depression in a middle-income country: feasibility of an fMRI protocol and preliminary results.

Thu, 08/08/2019 - 14:20
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Neuroimaging adolescents with depression in a middle-income country: feasibility of an fMRI protocol and preliminary results.

Braz J Psychiatry. 2019 Aug 05;:

Authors: Battel L, Swartz J, Anes M, Manfro PH, Rohde LA, Viduani A, Mondelli V, Kieling C

Abstract
OBJECTIVE: To test the feasibility and to present preliminary results of a neuroimaging protocol to evaluate adolescent depression in a middle-income setting.
METHODS: We assessed psychotropic medication-free adolescents (age range 14-16 years) with a diagnosis of major depressive disorder (MDD). Participants underwent a comprehensive clinical evaluation and both structural and functional magnetic resonance imaging (fMRI). In this pilot study, a preliminary single-group analysis of resting-state fMRI (rs-fMRI) data was performed, with a focus on the default mode network (DMN), cognitive control network (CCN), and salience network (SN).
RESULTS: The sample included 29 adolescents with MDD (mean age 16.01, SD 0.78) who completed the protocol. Only two participants were excluded due to MRI quality issues (head movement), and were not included in the analyses. The scans showed significant connectivity between the medial prefrontal cortex and posterior cingulate cortex (DMN), the ACC and anterior insula (SN), and the lateral prefrontal cortex and dorsal parietal cortex (CCN).
CONCLUSION: We demonstrated the feasibility of implementing a complex neuroimaging protocol in a middle-income country. Further, our preliminary rs-fMRI data revealed patterns of resting-state connectivity consistent with prior research performed in adolescents from high-income countries.

PMID: 31389498 [PubMed - as supplied by publisher]

Recording brain activity can function as an implied social presence and alter neural connectivity.

Thu, 08/08/2019 - 14:20
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Recording brain activity can function as an implied social presence and alter neural connectivity.

Cogn Neurosci. 2019 Aug 07;:1-8

Authors: Turner BO, Kingstone A, Risko EF, Santander T, Li J, Miller MB

Abstract
People often behave differently when they know they are being watched. Here, we report the first investigation of whether such social presence effects also include brain monitoring technology, and also their impacts on the measured neural activity. We demonstrate that merely informing participants that fMRI has the potential to observe (thought-related) brain activity is sufficient to trigger changes in functional connectivity within and between relevant brain networks that have been previously associated selectively with executive and attentional control as well as self-relevant processing, social cognition, and theory of mind. These results demonstrate that an implied social presence, mediated here by recording brain activity with fMRI, can alter brain functional connectivity. These data provide a new manipulation of social attention, as well as shining light on a methodological hazard for researchers using equipment to monitor brain activity.

PMID: 31389302 [PubMed - as supplied by publisher]

High resolution resting state functional connectivity of the extended amygdala.

Thu, 08/08/2019 - 14:20
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High resolution resting state functional connectivity of the extended amygdala.

Brain Connect. 2019 Aug 07;:

Authors: Weis C, Huggins AA, Bennett KP, Parisi EA, Larson CL

Abstract
The extended amygdala has been implicated as a critical region in the neurocircuitry underlying anxiety. The circuitry of the extended amygdala, including the central (CeA) and basolateral (BLA) nuclei of the amygdala and the bed nucleus of the stria terminalis (BNST), has been well-defined in non-human animals; however, much less is known about the roles and interactions of these structures in humans given their small size. Therefore, the current study used high-resolution 7-Tesla MRI to define, compare, and contrast functional connectivity (FC) of these structures in 57 neurologically healthy young adults. In addition, FC was investigated in relation to self-reported measures of anxiety and intolerance of uncertainty, a key feature of anxiety. Results of the FC analysis of each of the nuclei largely replicated previous work. Conjunction analyses showed nuclei of the extended amygdala shared FC with hippocampal, cingulate, medial prefrontal, and subgenual cortices. Comparison of seed-to-voxel time series correlation maps demonstrated that compared to the BNST, the CeA and BLA were more strongly coupled with parahippocampal, temporal, fusiform, and occipital gyri. Relative to the CeA and BLA, the BNST was more strongly coupled with the anterior caudate and anterior cingulate cortex. Finally, greater trait anxiety and intolerance of uncertainty were related to greater FC of the extended amygdala and posterior cingulate and temporal cortices and decreased FC with the parahippocampal and insular cortices. Results of this study extend previous work to provide more clarity of the nuances of extended amygdala FC and its relationship with anxiety.

PMID: 31389253 [PubMed - as supplied by publisher]

Differentiation of Early Alzheimer's Disease, Mild Cognitive Impairment and Cognitively Healthy Elderly Samples using Multimodal Neuroimaging Indices.

Thu, 08/08/2019 - 14:20
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Differentiation of Early Alzheimer's Disease, Mild Cognitive Impairment and Cognitively Healthy Elderly Samples using Multimodal Neuroimaging Indices.

Brain Connect. 2019 Aug 07;:

Authors: Joshi H, Bharath S, Balachandar R, Sadanand S, Vishwakarma H, Aiyappan S, Saini J, Kumar KJ, John JP, Varghese M

Abstract
Brain resting state functional connectivity, white matter integrity and cortical morphometry as well as neuropsychological performance have seldom been studied together to differentiate Alzheimer's disease (AD), mild cognitive impairment (MCI) and elderly cognitively healthy comparison (eCHC) samples in the context of the same study. We examined brain resting state functional connectivity (rsFC) in samples of patients with mild AD (n=50) and MCI (n=49) in comparison to eCHC samples (n=48) and then explored whether rsFC abnormalities can be linked to underlying gray matter volumetric and/or white matter microstructural abnormalities. The mild AD sample showed significantly increased rsFC in Executive control network (ECN) and Dorsal attention network (DAN) compared to eCHC sample, and increased rsFC in ECN compared to MCI. Brain regions corresponding to both these resting state networks (RSNs) showed significant reduction in fractional anisotropy in mild AD in comparison to eCHC. Significant gray matter volumetric reductions were observed in brain regions corresponding to both RSNs in the mild AD sample compared to MCI as well as eCHC samples. The association of Default mode network (DMN)-DAN anticorrelation with cognitive performances differentiated mild AD and MCI from eCHC sample. These findings highlight the association between brain structural and functional abnormalities as well as cognitive impairment that enables differentiation between early AD, MCI and eCHC samples.

PMID: 31389245 [PubMed - as supplied by publisher]

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