New resting-state fMRI related studies at PubMed

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Altered functional connectivity density in the brains of hemodialysis end-stage renal disease patients: An in vivo resting-state functional MRI study.

Wed, 01/01/2020 - 14:00
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Altered functional connectivity density in the brains of hemodialysis end-stage renal disease patients: An in vivo resting-state functional MRI study.

PLoS One. 2019;14(12):e0227123

Authors: Shi Y, Tong C, Zhang M, Gao X

Abstract
BACKGROUND: End-stage renal disease (ESRD) patients usually suffer from a high prevalence of central nervous system abnormalities, including cognitive impairment and emotional disorders, which severely influence their quality of life. There have been many neuroimaging research developments in ESRD patients with brain function abnormalities; however, the dysfunction of the salience network (SN) of them has received little attention. The purpose of this study was to investigate the changes of global functional connectivity density (gFCD) in brains of ESRD patients undergoing hemodialysis using resting-state functional magnetic resonance imaging (re-fMRI).
METHODS: re-fMRI data were collected from 30 ESRD patients undergoing hemodialysis (14 men, 38.33±7.44 years old) and 30 matched healthy controls (13 men, 39.17±5.7 years old). Neuropsychological tests including the Montreal Cognitive Assessment (MoCA) and Beck Depression Inventory (BDI) were used to evaluate the neurocognitive and psychiatric conditions of the subjects. Blood biochemistry tests, including hemoglobin level, serum albumin level, blood urea level, serum phosphate, serum calcium, and parathyroid hormone level, and dialysis-related indicators, including blood pressure fluctuations in dialysis, single-pool Kt/V(spKt/V), and ultrafiltration volume of dialysis were obtained from the ESRD patients. A two-sample t-test was used to examine the group differences in gFCD between ESRD patients and healthy controls after controlling for age, gender and education.
RESULTS: Compared with healthy controls, ESRD patients exhibited a significantly increased gFCD in the salience network, including the bilateral insula, and dorsal anterior cingulated cortex (dACC), and there was no significant correlation between gFCD and the structural mean grey matter volume in patients for every cluster in the brain regions showing significant different gFCD between the two groups. Furthermore, there were significant negative correlations between the degree of connectivity in the right insula and spKt/V.
CONCLUSION: Our findings revealed abnormal intrinsic dysconnectivity pattern of salience network-related regions in ESRD patients from the whole brain network perspective. The negative correlation between the right insula and spKt/V suggested that increased fractional removal of urea may reduce the pathological activity in the insula.

PMID: 31891646 [PubMed - in process]

Connectivity differences between Gulf War Illness (GWI) phenotypes during a test of attention.

Wed, 01/01/2020 - 14:00
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Connectivity differences between Gulf War Illness (GWI) phenotypes during a test of attention.

PLoS One. 2019;14(12):e0226481

Authors: Clarke T, Jamieson JD, Malone P, Rayhan RU, Washington S, VanMeter JW, Baraniuk JN

Abstract
One quarter of veterans returning from the 1990-1991 Persian Gulf War have developed Gulf War Illness (GWI) with chronic pain, fatigue, cognitive and gastrointestinal dysfunction. Exertion leads to characteristic, delayed onset exacerbations that are not relieved by sleep. We have modeled exertional exhaustion by comparing magnetic resonance images from before and after submaximal exercise. One third of the 27 GWI participants had brain stem atrophy and developed postural tachycardia after exercise (START: Stress Test Activated Reversible Tachycardia). The remainder activated basal ganglia and anterior insulae during a cognitive task (STOPP: Stress Test Originated Phantom Perception). Here, the role of attention in cognitive dysfunction was assessed by seed region correlations during a simple 0-back stimulus matching task ("see a letter, push a button") performed before exercise. Analysis was analogous to resting state, but different from psychophysiological interactions (PPI). The patterns of correlations between nodes in task and default networks were significantly different for START (n = 9), STOPP (n = 18) and control (n = 8) subjects. Edges shared by the 3 groups may represent co-activation caused by the 0-back task. Controls had a task network of right dorsolateral and left ventrolateral prefrontal cortex, dorsal anterior cingulate cortex, posterior insulae and frontal eye fields (dorsal attention network). START had a large task module centered on the dorsal anterior cingulate cortex with direct links to basal ganglia, anterior insulae, and right dorsolateral prefrontal cortex nodes, and through dorsal attention network (intraparietal sulci and frontal eye fields) nodes to a default module. STOPP had 2 task submodules of basal ganglia-anterior insulae, and dorsolateral prefrontal executive control regions. Dorsal attention and posterior insulae nodes were embedded in the default module and were distant from the task networks. These three unique connectivity patterns during an attention task support the concept of Gulf War Disease with recognizable, objective patterns of cognitive dysfunction.

PMID: 31891592 [PubMed - in process]

A network clustering based feature selection strategy for classifying autism spectrum disorder.

Wed, 01/01/2020 - 14:00
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A network clustering based feature selection strategy for classifying autism spectrum disorder.

BMC Med Genomics. 2019 Dec 30;12(Suppl 7):153

Authors: Tang L, Mostafa S, Liao B, Wu FX

Abstract
BACKGROUND: Advanced non-invasive neuroimaging techniques offer new approaches to study functions and structures of human brains. Whole-brain functional networks obtained from resting state functional magnetic resonance imaging has been widely used to study brain diseases like autism spectrum disorder (ASD). Auto-classification of ASD has become an important issue. Existing classification methods for ASD are based on features extracted from the whole-brain functional networks, which may be not discriminant enough for good performance.
METHODS: In this study, we propose a network clustering based feature selection strategy for classifying ASD. In our proposed method, we first apply symmetric non-negative matrix factorization to divide brain networks into four modules. Then we extract features from one of four modules called default mode network (DMN) and use them to train several classifiers for ASD classification.
RESULTS: The computational experiments show that our proposed method achieves better performances than those trained with features extracted from the whole brain network.
CONCLUSION: It is a good strategy to train the classifiers for ASD based on features from the default mode subnetwork.

PMID: 31888621 [PubMed - in process]

Altered functional connectivity of the nucleus accumbens subdivisions in amphetamine-type stimulant abusers: a resting-state fMRI study.

Wed, 01/01/2020 - 14:00
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Altered functional connectivity of the nucleus accumbens subdivisions in amphetamine-type stimulant abusers: a resting-state fMRI study.

BMC Neurosci. 2019 Dec 30;20(1):66

Authors: Wang Y, Yan KJ, Fan CX, Luo XN, Zhou Y

Abstract
BACKGROUND: The growing abuse of amphetamine-type stimulants leads to new challenges to human health. A possible addiction mechanism has been proposed by altered functional architecture of the nucleus accumbens (NAc) during resting state. NAc contains different subdivisions and they may play different roles in addiction. The aim of the present study was to examine whether there are common or distinct patterns of functional connectivity of the NAc subdivisions in amphetamine-type stimulant abusers (ATSAs).
METHODS: The present study recruited 17 male ATSAs and 22 healthy male controls. All the subjects underwent resting-state functional magnetic resonance imaging (fMRI) with their eyes closed. The NAc was divided into core-like and shell-like subdivisions. We used seed-based resting-state functional connectivity (RSFC) analyses to identify differences in brain functional architecture between ATSAs and healthy controls (HCs).
RESULTS: ATSAs had lower positive RSFCs with all of the NAc subdivisions over the left orbital part of superior frontal gyrus and higher positive RSFCs with the NAc subdivisions over the left opercular part of inferior frontal gyrus than HCs, which indicates common abnormalities across the NAc subdivisions in ATSAs. In addition, the RSFCs between the NAc subdivisions and the left orbital part of superior frontal gyrus were negatively correlated with the addiction severity in ATSAs.
CONCLUSION: These results provide evidence that there are common RSFC patterns of the NAc subdivisions in ATSAs. The abnormality indicated by disrupted functional connectivity between the NAc subdivisions and prefrontal cortex suggests abnormal interaction between the rewarding process and cognitive control in ATSAs. Our results shed insight on the neurobiological mechanisms of ATSA and suggest potential novel therapeutic targets for treatment and intervention of ATSAs.

PMID: 31888484 [PubMed - in process]

Resting-state connectivity and the effects of treatment in restless legs syndrome.

Tue, 12/31/2019 - 13:00
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Resting-state connectivity and the effects of treatment in restless legs syndrome.

Sleep Med. 2019 Nov 18;67:33-38

Authors: Lee YS, Ku J, Kim KT, Chang H, Earley CJ, Allen RP, Cho YW

Abstract
OBJECTIVES: Resting-state brain connectivity has been shown to differ for Restless Legs Syndrome (RLS) compared to healthy control (CON) groups. This study evaluates the degree these RLS-CON differences are changed by concurrent treatment.
METHODS: Resting-state functional MRIs were obtained from 32 idiopathic RLS patients during the morning asymptomatic period and 16 age and gender-matched CON subjects. Of the 32 RLS patients, 16 were drug-naïve (DN-RLS), and 16 were regularly drug-treated using a dopamine agonist (DT-RLS). Various assessments of disease characteristics were also performed. The primary purpose was to assess the replicability of prior results and the effects of treatment on these differences between controls and untreated RLS patients. Resting-state connectivity was analyzed by a seed-based method using the bilateral ventral-posterolateral nuclei (VPLN) in the thalamus.
RESULTS: In the DN-RLS group, compared to the CON group, three areas (the bilateral lingual gyri and right middle temporal gyrus) were replicated. The three replicated areas did not significantly differ for DT-RLS compared to DN-RLS. DT-RLS compared to DN-RLS had significantly higher thalamic connectivity for the left uvula, right tuber, left anterior insula, and right declive.
CONCLUSIONS: Thalamic connectivity to the bilateral lingual gyri and right middle temporal gyrus is a replicable finding in DN-RLS that was not affected by dopamine agonist treatments. Other changes in thalamic connectivity were altered by dopamine agonist treatment. These treatment effects may be pertinent to the known treatment benefits of a dopamine agonist on RLS symptoms.

PMID: 31887606 [PubMed - as supplied by publisher]

Hybrid modeling of alpha rhythm and the amplitude of low-frequency fluctuations abnormalities in the thalamocortical region and basal ganglia in Alzheimer disease.

Tue, 12/31/2019 - 13:00
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Hybrid modeling of alpha rhythm and the amplitude of low-frequency fluctuations abnormalities in the thalamocortical region and basal ganglia in Alzheimer disease.

Eur J Neurosci. 2019 Dec 30;:

Authors: Cakir Y

Abstract
A hybrid computational model of thalamo-cortical circuitry and basal ganglia is proposed to investigate the relation between the fractional amplitude of low-frequency fluctuations (fALFF) in the resting state functional magnetic resonance imaging (rs-fMRI) in the striatum and electroencephalogram (EEG) changes within the alpha frequency bands in thalamic region in the case of Alzheimer's disease (AD). For that purpose, an Izikhevich neuron model based network of the basal ganglia region is constructed and connected with the thalamic region which is modeled as neural mass. By considering the neurodegenerative changes in AD, the network dynamics are analyzed. The relation between the neural activity of basal ganglia and AD is investigated by modeling the blood oxygenation level-dependent (BOLD) signal. Decrease in fALFF of slow-4 band in the simulated BOLD signal of the striatum is observed. Since the thalamic region receive inhibitory connections from basal ganglia over Globus Palidus internal segment (GPi), the parameter changes emulating AD degenerations in the striatum increased the inhibitory effect on the thalamic network and as a result, slowing in alpha rhythms is observed. It is observed that the decrease in the synaptic strength between the neurons in the striatum has a dominant effect on the slowing in alpha rhythm, also causes a decrease in fALFF of slow-4 band in striatum. This demonstrates a close and causal relation between the decrease in fALFF in the striatum and the slowing in alpha rhythms in the thalamic region in AD.

PMID: 31887242 [PubMed - as supplied by publisher]

Dorsal striatal functional connectivity changes in Internet gaming disorder: A longitudinal magnetic resonance imaging study.

Tue, 12/31/2019 - 13:00
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Dorsal striatal functional connectivity changes in Internet gaming disorder: A longitudinal magnetic resonance imaging study.

Addict Biol. 2019 Dec 30;:e12868

Authors: Lee D, Namkoong K, Lee J, Jung YC

Abstract
Internet gaming disorder (IGD) is a behavioral addiction involving excessive online game use despite negative psychosocial consequences. Unrestricted online gaming may lead to changes in striatal activity and the relationship between the striatum and other cortical regions. This study investigated structural and functional abnormalities involving the striatum through longitudinal follow-up magnetic resonance imaging (MRI) assessments. Eighteen young males with IGD (mean age: 23.8 ± 2.0 years) and 18 controls (mean age: 23.9 ± 2.7 years) were evaluated. Subjects were reassessed ≥1 year after the first visit (mean follow-up duration: 22.8 ± 6.7 months), using voxel-based morphometry and seed-based resting-state functional connectivity (FC) analyses in seed regions of the dorsal and ventral striatum. Subjects with IGD had smaller gray matter volume (GMV) in the anterior/middle cingulate cortex compared with controls during initial and follow-up assessments. They exhibited decreased FC between the left dorsal putamen and left medial prefrontal cortex (mPFC) compared with controls. They exhibited increased FC strength between the right dorsal putamen and right middle occipital gyrus (MOG) during follow-up. Subjects with IGD showed a significant correlation between changes in the dorsal putamen-MOG FC and gaming time per day. Young males with IGD showed an altered FC pattern in the dorsal striatum during follow-up. FC of the dorsal striatum in IGD increased in the mPFC and decreased in the MOG. These findings showed that IGD was accompanied by weakening of prefrontal control and strengthening of the sensorimotor network, suggesting that uncontrolled gaming may be related with functional neural changes in the dorsal striatum.

PMID: 31886611 [PubMed - as supplied by publisher]

The Cerebellum Posterior Lobe Associates with the Exophthalmos of Primary Hyperthyroidism: A Resting-State fMRI Study.

Tue, 12/31/2019 - 13:00
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The Cerebellum Posterior Lobe Associates with the Exophthalmos of Primary Hyperthyroidism: A Resting-State fMRI Study.

Int J Endocrinol. 2019;2019:8135671

Authors: Liu WF, Shu YQ, Zhu PW, Li B, Shi WQ, Lin Q, Liu YX, Zhang MY, Min YL, Yuan Q, Shao Y

Abstract
Background: Exophthalmos occurs in patients with primary hyperthyroidism. There were few studies about the changes of brain functional networks of patients with exophthalmos of primary hyperthyroidism (EOPH). However, differences in spontaneous brain activity in patients with EOPH remain unclear.
Objective: This study explored alterations in the brain functional networks of patients with EOPH using a voxel-wise degree centrality (DC) method.
Methods: A total of 20 patients with EOPH (8 men and 12 women) were enrolled. In addition, 20 patients with primary hyperthyroidism without exophthalmos, matched in age, sex, and education status, were enrolled as a control group. The Hospital Anxiety and Depression Scale was used to assess the anxiety and depression status of participants. All participants were examined using resting-state functional MRI. Changes in spontaneous brain activity were investigated using the DC method. To distinguish between the DC values of the patients with EOPH and those of the control group, we analyzed the receiver operating characteristic (ROC) curve. The interrelationships between the DC values and clinical variables in the patients with EOPH were evaluated using Pearson's correlation coefficient.
Results: Patients with EOPH exhibited notably lower DC values in the cerebellum posterior lobe than the control group. In addition, there were negative correlations between the anxiety scores (AS) and the depression scores (DS) and DC values of the cerebellum posterior lobe. The ROC curve analysis of the cerebellum posterior lobe demonstrated that the area under the curve method had a high diagnostic accuracy.
Conclusions: Our study was the first, to our knowledge, to explore changes in the brains of patients with EOPH using the DC method. The DC value was significantly different in the cerebellum posterior lobe in patients with EOPH, indicating that the cerebellum posterior lobe is associated with EOPH.

PMID: 31885561 [PubMed]

Altered Amplitude of Low-Frequency Fluctuations in Inactive Patients with Nonneuropsychiatric Systemic Lupus Erythematosus.

Tue, 12/31/2019 - 13:00
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Altered Amplitude of Low-Frequency Fluctuations in Inactive Patients with Nonneuropsychiatric Systemic Lupus Erythematosus.

Neural Plast. 2019;2019:9408612

Authors: Yu Y, Chen L, Wang Q, Hu L, Ding Q, Jia X, Yang X

Abstract
Objective: This study is aimed at investigating the characteristics of the spontaneous brain activity in inactive patients with nonneuropsychiatric systemic lupus erythematosus (non-NPSLE).
Methods: Thirty-one female inactive patients with non-NPSLE and twenty healthy controls were examined by resting-state functional magnetic resonance imaging (RS-fMRI). Three amplitude methods including amplitude of low-frequency fluctuations (ALFF), fractional amplitude of low-frequency fluctuations (fALFF), and percent amplitude of fluctuation (PerAF) (with and without standardization) were applied to evaluate the spontaneous brain activity. The correlation was performed between low-frequency oscillations and clinical and neuropsychological factors in inactive patients with non-NPSLE.
Results: Compared to healthy controls, patients with non-NPSLE showed increased standardized ALFF (mALFF) in the left inferior temporal gyrus and left putamen, decreased PerAF in the right postcentral gyrus and bilateral precentral gyrus, and increased standardized PerAF (mPerAF) in the left putamen and decreased mPerAF in the right postcentral gyrus and bilateral precentral gyrus. By standardized fALFF (mfALFF), no significant brain regions were found between the two groups. Correlation analysis revealed significantly positive correlations between glucocorticoid dose and PerAF in the right precentral gyrus and mPerAF in the left putamen, and Complement 3 (C3) and mPerAF in the right postcentral gyrus. There was a significant negative correlation between C3 and mALFF in the left putamen.
Conclusion: Abnormal low-frequency oscillations in multiple brain regions were found in inactive patients with non-NPSLE, indicating that the alteration of mALFF, PerAF, and mPerAF in specific brain regions might be an imaging biomarker of brain dysfunction in inactive patients with non-NPSLE.

PMID: 31885539 [PubMed - in process]

Atypical relationships between spontaneous EEG and fMRI activity in autism.

Tue, 12/31/2019 - 13:00
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Atypical relationships between spontaneous EEG and fMRI activity in autism.

Brain Connect. 2019 Dec 30;:

Authors: Mash LE, Keehn B, Linke AC, Liu T, Helm JL, Haist F, Townsend J, Müller RA

Abstract
Autism spectrum disorders (ASDs) have been linked to atypical communication among distributed brain networks. However, despite decades of research, the exact nature of differences between typically developing (TD) individuals and those with ASDs remains unclear. ASDs have been widely studied using resting state neuroimaging methods, including both functional MRI (fMRI) and electroencephalography (EEG). However, little is known about how fMRI and EEG measures of spontaneous brain activity are related in ASDs. In the current study, two cohorts of children and adolescents underwent resting-state EEG (n = 38 per group) or fMRI (n = 66 ASD, 57 TD), with a subset of individuals in both the EEG and fMRI cohorts (n = 17 per group). In the EEG cohort, occipito-parietal EEG alpha power was found to be reduced in ASDs. In the fMRI cohort, blood oxygen level-dependent (BOLD) power was regionally increased in right temporal regions and there was widespread overconnectivity between thalamus and cortical regions in the ASD group relative to the TD group. Finally, multimodal analyses found that while TD children showed consistently positive relationships between EEG alpha power and regional BOLD power, these associations were weak or negative in ASDs. These findings suggest atypical links between alpha rhythms and regional BOLD activity in ASDs, possibly implicating neural substrates and processes that coordinate thalamocortical regulation of the alpha rhythm.

PMID: 31884804 [PubMed - as supplied by publisher]

Aberrant Somatosensory Processing and Connectivity in Mice Lacking Engrailed-2.

Tue, 12/31/2019 - 13:00
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Aberrant Somatosensory Processing and Connectivity in Mice Lacking Engrailed-2.

J Neurosci. 2019 02 20;39(8):1525-1538

Authors: Chelini G, Zerbi V, Cimino L, Grigoli A, Markicevic M, Libera F, Robbiati S, Gadler M, Bronzoni S, Miorelli S, Galbusera A, Gozzi A, Casarosa S, Provenzano G, Bozzi Y

Abstract
Overreactivity and defensive behaviors in response to tactile stimuli are common symptoms in autism spectrum disorder (ASD) patients. Similarly, somatosensory hypersensitivity has also been described in mice lacking ASD-associated genes such as Fmr1 (fragile X mental retardation protein 1). Fmr1 knock-out mice also show reduced functional connectivity between sensory cortical areas, which may represent an endogenous biomarker for their hypersensitivity. Here, we measured whole-brain functional connectivity in Engrailed-2 knock-out (En2 -/-) adult mice, which show a lower expression of Fmr1 and anatomical defects common to Fmr1 knock-outs. MRI-based resting-state functional connectivity in adult En2 -/- mice revealed significantly reduced synchronization in somatosensory-auditory/associative cortices and dorsal thalamus, suggesting the presence of aberrant somatosensory processing in these mutants. Accordingly, when tested in the whisker nuisance test, En2 -/- but not WT mice of both sexes showed fear behavior in response to repeated whisker stimulation. En2 -/- mice undergoing this test exhibited decreased c-Fos-positive neurons (a marker of neuronal activity) in layer IV of the primary somatosensory cortex and increased immunoreactive cells in the basolateral amygdala compared with WT littermates. Conversely, when tested in a sensory maze, En2 -/- and WT mice spent a comparable time in whisker-guided exploration, indicating that whisker-mediated behaviors are otherwise preserved in En2 mutants. Therefore, fearful responses to somatosensory stimuli in En2 -/- mice are accompanied by reduced basal connectivity of sensory regions, reduced activation of somatosensory cortex, and increased activation of the basolateral amygdala, suggesting that impaired somatosensory processing is a common feature in mice lacking ASD-related genes.SIGNIFICANCE STATEMENT Overreactivity to tactile stimuli is a common symptom in autism spectrum disorder (ASD) patients. Recent studies performed in mice bearing ASD-related mutations confirmed these findings. Here, we evaluated the behavioral response to whisker stimulation in mice lacking the ASD-related gene Engrailed-2 (En2 -/- mice). Compared with WT controls, En2 -/- mice showed reduced functional connectivity in the somatosensory cortex, which was paralleled by fear behavior, reduced activation of somatosensory cortex, and increased activation of the basolateral amygdala in response to repeated whisker stimulation. These results suggest that impaired somatosensory signal processing is a common feature in mice harboring ASD-related mutations.

PMID: 30593497 [PubMed - indexed for MEDLINE]

Independent support for corticopallidal contributions to schizophrenia-related functional impairment.

Sun, 12/29/2019 - 17:00
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Independent support for corticopallidal contributions to schizophrenia-related functional impairment.

Schizophr Res. 2019 Dec 24;:

Authors: Tarcijonas G, Foran W, Blazer A, Eack SM, Luna B, Sarpal DK

Abstract
BACKGROUND: Abnormalities between the prefrontal cortex and basal ganglia have been described by numerous studies of schizophrenia (SZ). We recently reported that individuals with first episode SZ who develop greater vocational and social impairments show lower baseline functional connectivity between the globus pallidus (GP) and regions of the intrinsic salience network. Here we extend these findings to probe the integrity of this system in individuals with chronic illness.
METHODS: All data were obtained from a publicly available Center of Biomedical Research Excellence dataset (http://fcon_1000.
PROJECTS: nitric.org/indi/retro/cobre.html) that included resting-state fMRI and structural scans, and an array of clinical and neuropsychological measures. Participants with SZ were divided into high- or low-functioning groups based on scores across measures of psychopathology and cognitive functioning. Corticopallidal functional connectivity was examined between low- and high-functioning individuals with SZ and matched healthy control participants. We focused on connectivity between GP structures and a priori regions of the salience network that were significant in our previous study. Exploratory voxel-wise analyses were also conducted.
RESULTS: Lower functioning individuals with SZ demonstrated less connectivity between bilateral GP externa and nodes within the salience network, relative to healthy controls. No connectivity differences were observed between low- and high-functioning individuals with SZ. Exploratory voxel-wise analyses highlighted additional large-scale corticopallidal abnormalities in lower-functioning participants with SZ.
CONCLUSIONS: These results confirm our previous work in a more chronic cohort of individuals with SZ. Our findings further advance corticopallidal connectivity as a biomarker of functional impairments in SZ and lay the groundwork for treatment-based studies.

PMID: 31882276 [PubMed - as supplied by publisher]

Disrupted salience network dynamics in Parkinson's disease patients with impulse control disorders.

Sat, 12/28/2019 - 16:00
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Disrupted salience network dynamics in Parkinson's disease patients with impulse control disorders.

Parkinsonism Relat Disord. 2019 Dec 16;70:74-81

Authors: Navalpotro-Gomez I, Kim J, Paz-Alonso PM, Delgado-Alvarado M, Quiroga-Varela A, Jimenez-Urbieta H, Carreiras M, Strafella AP, Rodriguez-Oroz MC

Abstract
BACKGROUND: Dynamic functional network analysis may add relevant information about the temporal nature of the neurocognitive alterations in PD patients with impulse control disorders (PD-ICD). Our aim was to investigate changes in dynamic functional network connectivity (dFNC) in PD-ICD patients, and topological properties of such networks.
METHODS: Resting state fMRI was performed on 16 PD PD-ICD patients, 20 PD patients without ICD and 17 healthy controls, whose demographic, clinical and behavioral scores were assessed. We conducted a group spatial independent component analysis, sliding window and graph-theory analyses.
RESULTS: PD-ICD patients, in contrast to PD-noICD and HC subjects, were engaged across time in a brain configuration pattern characterized by a lack of between-network connections at the expense of strong within-network connections (State III) in temporal, frontoinsular and cingulate cortices, all key nodes of the salience network. Moreover, this increased maintenance of State III in PD-ICD patients was positively correlated with the severity of impulsivity and novelty seeking as measured by specific scales. While in State III, these patients also exhibited increased local efficiency in all the aforementioned areas.
CONCLUSIONS: Our findings show for the first time that PD-ICD patients have a dynamic functional engagement of local connectivity involving the limbic circuit, leading to the inefficient modulation in emotional processing and reward-related decision-making. These results provide new insights into the pathophysiology of ICD in PD patients and indicate that the dFC study of fMRI could be a useful biomarker to identify patients at risk to develop ICD.

PMID: 31881521 [PubMed - as supplied by publisher]

Individual Resting-State Brain Networks enabled by Massive Multivariate Conditional Mutual Information.

Sat, 12/28/2019 - 16:00
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Individual Resting-State Brain Networks enabled by Massive Multivariate Conditional Mutual Information.

IEEE Trans Med Imaging. 2019 Dec 26;:

Authors: Sundaram P, Luessi M, Bianciardi M, Stufflebeam S, Hamalainen M, Solo V

Abstract
Individual-level resting-state networks (RSNs) based on resting-state fMRI (rs-fMRI) are of great interest due to evidence that network dysfunction may underlie some diseases. Most current rs-fMRI analyses use linear correlation. Since correlation is a bivariate measure of association, it discards most of the information contained in the spatial variation of the thousands of hemodynamic signals within the voxels in a given brain region. Subject-specific functional RSNs using typical rsfMRI data, are therefore dominated by indirect connections and loss of spatial information and can only deliver reliable connectivity after group averaging. While bivariate partial correlation can rule out indirect connections, it results in connectivity that is too sparse due to lack of sensitivity. We have developed a method that uses all the spatial variation information in a given parcel by employing a multivariate information-theoretic association measure based on canonical correlations. Our method, multivariate conditional mutual information (mvCMI) reliably constructs single-subject connectivity estimates showing mostly direct connections. Averaging across subjects is not needed. The method is applied to Human Connectome Project data and compared to diffusion MRI. The results are far superior to those obtained by correlation and partial correlation.

PMID: 31880547 [PubMed - as supplied by publisher]

Amisulpride and l-DOPA modulate subcortical brain nuclei connectivity in resting-state pharmacologic magnetic resonance imaging.

Sat, 12/28/2019 - 16:00
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Amisulpride and l-DOPA modulate subcortical brain nuclei connectivity in resting-state pharmacologic magnetic resonance imaging.

Hum Brain Mapp. 2019 Dec 27;:

Authors: Grimm O, Kopfer V, Küpper-Tetzel L, Deppert V, Kuhn M, de Greck M, Reif A

Abstract
The precise understanding of the dopaminergic (DA) system and its pharmacological modifications is crucial for diagnosis and treatment of neuropsychiatric disorders, as well as for understanding basic processes, such as motivation and reward. We probed the functional connectivity (FC) of subcortical nuclei related to the DA system according to seed regions defined according to an atlas of subcortical nuclei. We conducted a large pharmaco-fMRI study using a double-blind, placebo-controlled design, where we examined the effect of l -DOPA, a dopamine precursor, and amisulpride, a D2/D3-receptor antagonist on resting-state FC in 45 healthy young adults using a cross-over design. We examined the FC of subcortical nuclei with connection to the reward system and their reaction to opposing pharmacological probing. Amisulpride increased FC from the putamen to the precuneus and from ventral striatum to precentral gyrus. l -DOPA increased FC from the ventral tegmental area (VTA) to the insula/operculum and between ventral striatum and ventrolateral prefrontal cortex and it disrupted ventral striatal and dorsal caudate FC with the medial prefrontal cortex. In an exploratory analysis, we demonstrated that higher self-rated impulsivity goes together with a significant increase in VTA-mid-cingulate gyrus FC during l -DOPA-challenge. Therefore, our DA challenge modulated distinct large-scale subcortical connectivity networks. A dopamine-boost can increase midbrain DA nuclei connectivity to the cortex. The involvement of the VTA-cingulum connectivity in dependence of impulsivity has implications for diagnosis and therapy in disorders like ADHD.

PMID: 31880365 [PubMed - as supplied by publisher]

Modeling Resilience to Damage in Multiple Sclerosis: Plasticity Meets Connectivity.

Sat, 12/28/2019 - 16:00
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Modeling Resilience to Damage in Multiple Sclerosis: Plasticity Meets Connectivity.

Int J Mol Sci. 2019 Dec 24;21(1):

Authors: Stampanoni Bassi M, Iezzi E, Pavone L, Mandolesi G, Musella A, Gentile A, Gilio L, Centonze D, Buttari F

Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by demyelinating white matter lesions and neurodegeneration, with a variable clinical course. Brain network architecture provides efficient information processing and resilience to damage. The peculiar organization characterized by a low number of highly connected nodes (hubs) confers high resistance to random damage. Anti-homeostatic synaptic plasticity, in particular long-term potentiation (LTP), represents one of the main physiological mechanisms underlying clinical recovery after brain damage. Different types of synaptic plasticity, including both anti-homeostatic and homeostatic mechanisms (synaptic scaling), contribute to shape brain networks. In MS, altered synaptic functioning induced by inflammatory mediators may represent a further cause of brain network collapse in addition to demyelination and grey matter atrophy. We propose that impaired LTP expression and pathologically enhanced upscaling may contribute to disrupting brain network topology in MS, weakening resilience to damage and negatively influencing the disease course.

PMID: 31878257 [PubMed - in process]

Correlates of Residual Limb Pain: From Residual Limb Length and Usage to Metabolites and Activity in Secondary Somatosensory Cortex.

Sat, 12/28/2019 - 16:00
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Correlates of Residual Limb Pain: From Residual Limb Length and Usage to Metabolites and Activity in Secondary Somatosensory Cortex.

IEEE Trans Neural Syst Rehabil Eng. 2019 01;27(1):96-104

Authors: Guo X, Lyu Y, Wang Z, Li Y, Xiang J, Pan C, Flor H, Tong S

Abstract
Most recent studies attribute residual limb pain to peripheral pathological changes of the stump. However, in this paper, we focus on its associations with the residual limb length, usage, as well as the metabolic and functional alterations of the brain. The secondary somatosensory cortex (S2), one important area involved in pain intensity discrimination, was selected as the region of interest. Twenty-two upper-limb amputees were recruited and divided into two groups, i.e., amputees with residual limb pain (9/22) and without residual limb pain (13/22). The residual limb length, usage, as well as the metabolite concentration, resting-state activity and BOLD responses to the tactile stimulation in the contralateral S2, were compared between the two groups and correlated with the pain intensity. The amputees with residual limb pain showed significantly shorter length and less usage of the residual limb than the amputees without residual limb pain, and the pain intensity was significantly negatively correlated with the residual limb length and usage. In addition, the pain intensity was significantly correlated with the tNAA/tCr ratio, resting-state fALFF in the slow-4 band, and BOLD response to the tactile stimulation in the contralateral S2, although there were no significant group differences. Regression analysis suggested that residual limb pain is associated with shorter residual limb length and less residual limb usage.

PMID: 30530331 [PubMed - indexed for MEDLINE]

Association of Intrinsic Brain Architecture With Changes in Attentional and Mood Symptoms During Development.

Fri, 12/27/2019 - 15:20
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Association of Intrinsic Brain Architecture With Changes in Attentional and Mood Symptoms During Development.

JAMA Psychiatry. 2019 Dec 26;:

Authors: Whitfield-Gabrieli S, Wendelken C, Nieto-Castañón A, Bailey SK, Anteraper SA, Lee YJ, Chai XQ, Hirshfeld-Becker DR, Biederman J, Cutting LE, Bunge SA

Abstract
Importance: Understanding the neurodevelopmental trajectory of psychiatric symptoms is important for improving early identification, intervention, and prevention of mental disorders.
Objective: To test whether the strength of the coupling of activation between specific brain regions, as measured by resting-state functional magnetic resonance imaging (fMRI), predicted individual children's developmental trajectories in terms of attentional problems characteristic of attention-deficit/hyperactivity disorder and internalizing problems characteristics of major depressive disorder (MDD).
Design, Setting, and Participants: A community cohort of 94 children was recruited from Vanderbilt University between 2010 and 2013. They were followed up longitudinally for 4 years and the data were analyzed from 2016 to 2019. Based on preregistered hypotheses and an analytic plan, we examined whether specific brain connectivity patterns would be associated with longitudinal changes in scores on the Child Behavior Checklist (CBCL), a parental-report assessment used to screen for emotional, behavioral, and social problems and to predict psychiatric illnesses.
Main Outcomes and Measures: We used the strength of resting-state fMRI connectivity at age 7 years to predict subsequent changes in CBCL measures 4 years later and investigated the mechanisms of change by associating brain connectivity changes with changes in the CBCL.
Results: We analyzed data from a longitudinal brain development study involving children assessed at age 7 years (n = 94; 41 girls [43.6%]) and 11 years (n = 54; 32 girls [59.3%]). As predicted, less positive coupling at age 7 years between the medial prefrontal cortex and dorsolateral prefrontal cortex (DLPFC) was associated with a decrease in attentional symptoms by age 11 years (t49 = 2.38; P = .01; β = 0.32). By contrast, a less positive coupling between a region implicated in mood, the subgenual anterior cingulate cortex (sgACC), and DLPFC at age 7 years was associated with an increase in internalizing (eg, anxiety/depression) behaviors by age 11 years (t49 = -2.4; P = .01; β = -0.30). Logistic regression analyses revealed that sgACC-DLPFC connectivity was a more accurate predictor than baseline CBCL measures for progression to a subclinical score on internalization (t50 = -2.61; P = .01; β = -0.29). We then replicated and extended the sgACC-DLPFC result in an independent sample of children with (n = 25) or without (n = 18) familial risk for MDD.
Conclusions and Relevance: These resting-state fMRI metrics are promising biomarkers for the early identification of children at risk of developing MDD or attention-deficit/hyperactivity disorder.

PMID: 31876910 [PubMed - as supplied by publisher]

Genetic polymorphism in catechol-O-methyltransferase associated with the functional connectivity of frontostriatal circuits in first episode schizophrenia patients.

Fri, 12/27/2019 - 15:20
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Genetic polymorphism in catechol-O-methyltransferase associated with the functional connectivity of frontostriatal circuits in first episode schizophrenia patients.

Eur J Neurosci. 2019 Dec 25;:

Authors: Kang Y, Zhang W, Lv Y, Xu H, Lin Y, Cai S, Wang J, Huang L

Abstract
Negative symptoms in schizophrenia have been associated with functional changes in frontostriatal pathways. Dysregulation of the dopamine signal in frontostriatal pathways leads to the symptomology observed in schizophrenia. Although the catechol-O-methyltransferase (COMT) gene, one of the susceptibility genes for schizophrenia, has been associated with dopamine activities in prefrontal and striatal regions, it is still unclear whether the disease state and COMT val158 met genotype have an interaction effect on the functional connectivity of frontostriatal pathways. In this study, we evaluated the possible interactions between COMT val158 met variations and the disease state on the resting state functional connectivity (RSFC) of frontostriatal pathways in fifty-one first episode schizophrenia (FES) patients (val/val: 29, met +: 22) with prominent negative symptoms and forty-eight healthy controls (val/val: 31, met +: 17). Regions of interest were defined by the result of a meta-analysis of frontostriatal pathways using the Neurosynth database. We found a significant genotype × disease interaction effect on the RSFC between the bilateral anterior cingulate (ACC) and right caudate, which overlapped with the main effect of the disease state. Behavioural regression analysis suggested that RSFC between the right ACC and right caudate correlated with the severity of SANS avolition apathy scores in patients who were met carriers but not in patients who were val homozygous. Our findings suggest that the RSFC of frontostriatal pathways may differentially affected by an individual's COMT val158 met genotype.

PMID: 31876034 [PubMed - as supplied by publisher]

Non-pharmacological and pharmacological interventions relieve insomnia symptoms by modulating a shared network: A controlled longitudinal study.

Fri, 12/27/2019 - 15:20
Related Articles

Non-pharmacological and pharmacological interventions relieve insomnia symptoms by modulating a shared network: A controlled longitudinal study.

Neuroimage Clin. 2019;22:101745

Authors: Feng F, Yu S, Wang Z, Wang J, Park J, Wilson G, Deng M, Hu Y, Yan B, Kong J

Abstract
BACKGROUND: Primary insomnia (PI) is one of the most common complaints among the general population. Both non-pharmacological and pharmacological therapies have proven effective in treating primary insomnia. However, the underlying mechanism of treatment remains unclear, and no studies have compared the underlying mechanisms of different treatments.
METHODS: In this study, we investigated gray matter volume (GMV) and resting-state functional connectivity (rsFC) changes following both pharmacological and non-pharmacological treatments in patients with PI. A total of 67 PI patients were randomized into benzodiazepine treatment, cupping treatment, or a wait-list control group for 4 weeks. The Pittsburgh Sleep Quality Index (PSQI), gray matter volume (GMV), and resting-state functional connectivity (rsFC) of the hippocampus were measured at the beginning and end of the experiment.
RESULTS: We found 1) significantly decreased PSQI scores in the cupping and benzodiazepine treatment groups compared to the control group with no significant differences between the two treatment groups; 2) significant GMV increases in the cupping group compared to the control group at the right hippocampus after 4 weeks of treatment; 3) significantly increased rsFC between the right hippocampus and left rostral anterior cingulate cortex/medial prefrontal cortex (rACC/mPFC) in the two treatment groups, which was significantly associated with PSQI score decreases.
DISCUSSION: Our findings suggest that benzodiazepine and cupping may share a common mechanism to relieve the symptoms of patients with PI.

PMID: 30878612 [PubMed - indexed for MEDLINE]

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