New resting-state fMRI related studies at PubMed

Subscribe to New resting-state fMRI related studies at PubMed feed New resting-state fMRI related studies at PubMed
NCBI: db=pubmed; Term=resting state fMRI
Updated: 5 hours 57 min ago

Functional MRI and resting state connectivity in white matter - a mini-review.

Sun, 08/04/2019 - 15:40

Functional MRI and resting state connectivity in white matter - a mini-review.

Magn Reson Imaging. 2019 Jul 31;:

Authors: Gore JC, Li M, Gao Y, Wu TL, Schilling KG, Huang Y, Mishra A, Newton AT, Rogers BP, Chen LM, Anderson AW, Ding Z

Abstract
Functional MRI (fMRI) signals are robustly detectable in white matter (WM) but they have been largely ignored in the fMRI literature. Their nature, interpretation, and relevance as potential indicators of brain function remain under explored and even controversial. Blood oxygenation level dependent (BOLD) contrast has for over 25 years been exploited for detecting localized neural activity in the cortex using fMRI. While BOLD signals have been reliably detected in grey matter (GM) in a very large number of studies, such signals have rarely been reported from WM. However, it is clear from our own and other studies that although BOLD effects are weaker in WM, using appropriate detection and analysis methods they are robustly detectable both in response to stimuli and in a resting state. BOLD fluctuations in a resting state exhibit similar temporal and spectral profiles in both GM and WM, and their relative low frequency (0.01-0.1 Hz) signal powers are comparable. They also vary with baseline neural activity e.g. as induced by different levels of anesthesia, and alter in response to a stimulus. In previous work we reported that BOLD signals in WM in a resting state exhibit anisotropic temporal correlations with neighboring voxels. On the basis of these findings, we derived functional correlation tensors that quantify the correlational anisotropy in WM BOLD signals. We found that, along many WM tracts, the directional preferences of these functional correlation tensors in a resting state are grossly consistent with those revealed by diffusion tensors, and that external stimuli tend to enhance visualization of specific and relevant fiber pathways. These findings support the proposition that variations in WM BOLD signals represent tract-specific responses to neural activity. We have more recently shown that sensory stimulations induce explicit BOLD responses along parts of the projection fiber pathways, and that task-related BOLD changes in WM occur synchronously with the temporal pattern of stimuli. WM tracts also show a transient signal response following short stimuli analogous to but different from the hemodynamic response function (HRF) characteristic of GM. Thus there is converging and compelling evidence that WM exhibits both resting state fluctuations and stimulus-evoked BOLD signals very similar (albeit weaker) to those in GM. A number of studies from other laboratories have also reported reliable observations of WM activations. Detection of BOLD signals in WM has been enhanced by using specialized tasks or modified data analysis methods. In this mini-review we report summaries of some of our recent studies that provide evidence that BOLD signals in WM are related to brain functional activity and deserve greater attention by the neuroimaging community.

PMID: 31376477 [PubMed - as supplied by publisher]

Abnormal synchronization of functional and structural networks in schizophrenia.

Sun, 08/04/2019 - 15:40
Related Articles

Abnormal synchronization of functional and structural networks in schizophrenia.

Brain Imaging Behav. 2019 Aug 02;:

Authors: Zhu J, Qian Y, Zhang B, Li X, Bai Y, Li X, Yu Y

Abstract
Synchronization is believed to play an important role in information processing of the brain. Mounting evidence supports the hypothesis that schizophrenia is related to impaired neural synchrony. However, most previous studies characterize brain synchronization from the perspective of temporal coordination of distributed neural activity, rather than network properties. Our aim was to investigate the network synchronization alterations in schizophrenia using publically available data. Resting-state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) were performed in 96 schizophrenia patients and 120 healthy controls. The whole-brain functional and structural networks were constructed and analyzed using graph theoretical approaches. Inter-group differences in network synchronization were investigated. Both the binary and weighted functional networks of schizophrenia patients exhibited decreased synchronizability (increased eigenratio) than those of healthy controls. With respect to the structural binary networks, schizophrenia patients showed a trend towards excessive synchronizability (decreased eigenratio). In addition, the excessive synchronizability of the structural binary networks was associated with more severe negative symptoms in schizophrenia patients. Our findings provide novel biological evidence that schizophrenia involves a disruption of neural synchrony from the perspective of network properties.

PMID: 31376115 [PubMed - as supplied by publisher]

Aberrant regional homogeneity in post-traumatic stress disorder after traffic accident: A resting-state functional MRI study.

Sat, 08/03/2019 - 15:00
Related Articles

Aberrant regional homogeneity in post-traumatic stress disorder after traffic accident: A resting-state functional MRI study.

Neuroimage Clin. 2019 Jul 22;24:101951

Authors: Fu S, Ma X, Li C, Wang T, Li C, Bai Z, Hua K, Yin Y, Wu Y, Yu K, Liu M, Ke Q, Tian J, Jiang G

Abstract
OBJECTIVES: The present study explored the changes in spontaneous regional activity in post-traumatic stress disorder (PTSD) patients, who experienced severe traffic accidents.
METHODS: 20 drug-naive PTSD patients and 18 healthy control subjects were imaged using resting-state functional magnetic resonance imaging (rs-fMRI) and analyzed by the algorithm of regional homogeneity (ReHo).
RESULTS: Compared to the healthy control group, the PTSD group showed decreased ReHo values in the right angular gyrus. In addition, a negative correlation was found between the activity level of the angular gyrus and the CAPS score.
CONCLUSION: The dysfunctions were found in the memory- and emotion-related areas, suggested a possible mechanism of memory dysregulation that might be related to the intrusive memory symptoms of PTSD. These results provided imaging evidence that might provide an in-depth understanding of the intrinsic functional architecture of PTSD.

PMID: 31374398 [PubMed - as supplied by publisher]

Objective and subjective measures of prior sleep-wake behavior predict functional connectivity in the default mode network during NREM sleep.

Sat, 08/03/2019 - 15:00
Related Articles

Objective and subjective measures of prior sleep-wake behavior predict functional connectivity in the default mode network during NREM sleep.

Brain Behav. 2019 01;9(1):e01172

Authors: Wilson RS, Mayhew SD, Rollings DT, Goldstone A, Hale JR, Bagshaw AP

Abstract
INTRODUCTION: Prior sleep behavior has been shown to correlate with waking resting-state functional connectivity (FC) in the default mode network (DMN). However, the impact of sleep history on FC during sleep has not been investigated. The aim of this study was to establish whether there is an association between intersubject variability in habitual sleep behaviors and the strength of FC within the regions of the DMN during non-rapid eye movement (NREM) sleep.
METHODS: Wrist actigraphy and sleep questionnaires were used as objective and subjective measures of habitual sleep behavior, and EEG-functional MRI during NREM sleep was used to quantify sleep.
RESULTS: There was a significant, regionally specific association between the interindividual variability in objective (total sleep time on the night before scanning) and subjective (Insomnia Severity Index) measures of prior sleep-wake behavior and the strength of DMN FC during subsequent wakefulness and NREM sleep. In several cases, FC was related to sleep measures independently of sleep stage, suggesting that previous sleep history effects sleep FC globally across the stages.
CONCLUSIONS: This work highlights the need to consider a subject's prior sleep history in studies utilizing FC analysis during wakefulness and sleep, and indicates the complexity of the impact of sleep on the brain both in the short and long term.

PMID: 30516035 [PubMed - indexed for MEDLINE]

Resting-state functional brain networks in adults with a new diagnosis of focal epilepsy.

Sat, 08/03/2019 - 15:00
Related Articles

Resting-state functional brain networks in adults with a new diagnosis of focal epilepsy.

Brain Behav. 2019 01;9(1):e01168

Authors: Alonazi BK, Keller SS, Fallon N, Adams V, Das K, Marson AG, Sluming V

Abstract
OBJECTIVES: Newly diagnosed focal epilepsy (NDfE) is rarely studied, particularly using advanced neuroimaging techniques. Many patients with NDfE experience cognitive impairments, particularly with respect to memory, sustained attention, mental flexibility, and executive functioning. Cognitive impairments have been related to alterations in resting-state functional brain networks in patients with neurological disorders. In the present study, we investigated whether patients with NDfE had altered connectivity in large-scale functional networks using resting-state functional MRI.
METHODS: We recruited 27 adults with NDfE and 36 age- and sex-matched healthy controls. Resting-state functional MRI was analyzed using the Functional Connectivity Toolbox (CONN). We investigate reproducibly determined large-scale functional networks, including the default mode, salience, fronto-parietal attention, sensorimotor, and language networks using a seed-based approach. Network comparisons between patients and controls were thresholded using a FDR cluster-level correction approach.
RESULTS: We found no significant differences in functional connectivity between seeds within the default mode, salience, sensorimotor, and language networks and other regions of the brain between patients and controls. However, patients with NDfE had significantly reduced connectivity between intraparietal seeds within the fronto-parietal attention network and predominantly frontal and temporal cortical regions relative to controls; this finding was demonstrated including and excluding the patients with brain lesions. No common alteration in brain structure was observed in patients using voxel-based morphometry. Findings were not influenced by treatment outcome at 1 year.
CONCLUSIONS: Patients with focal epilepsy have brain functional connectivity alterations at diagnosis. Functional brain abnormalities are not necessarily a consequence of the chronicity of epilepsy and are present when seizures first emerge.

PMID: 30488645 [PubMed - indexed for MEDLINE]

Frontostriatal Resting State Functional Connectivity in Resilient and Non-Resilient Adolescents with a Family History of Alcohol Use Disorder.

Fri, 08/02/2019 - 14:00
Related Articles

Frontostriatal Resting State Functional Connectivity in Resilient and Non-Resilient Adolescents with a Family History of Alcohol Use Disorder.

J Child Adolesc Psychopharmacol. 2019 Aug 01;:

Authors: Martz ME, Cope LM, Hardee JE, Brislin SJ, Weigard A, Zucker RA, Heitzeg MM

Abstract
Objectives: Youth with parental substance use disorder (family-history positive [FH+]) are at an elevated risk for substance use problems, but not all FH+ youth experience this outcome. Frontostriatal brain networks involved in inhibitory control and reward responsivity underlie risk-taking behaviors, but the role of these networks in substance use heterogeneity among FH+ youth has not been examined. The present study examined resting state functional connectivity (RSFC) in frontostriatal networks in FH+ youth with and without risky substance use. Methods: Participants were 36 FH+ adolescents (mean age 14.96 years at the scan date; 36% female) from a longitudinal, community-based functional magnetic resonance imaging study enriched for parental alcohol use disorder. Groups were based on the absence (resilient) or presence (high-risk) of at least one occasion of any substance use by age 14 and also use of at least two different types of substances by the most recent substance use assessment (mean age 16.89 years). Bilateral masks of the dorsolateral prefrontal cortex (DLPFC) and the nucleus accumbens were used for seed-based RSFC due to the importance of these regions in executive control and salience networks, respectively. Results: Compared with FH+/high-risk youth, FH+/resilient youth displayed greater connectivity between the left DLPFC seed and the left posterior cingulate cortex. No other brain regions showed significantly different RSFC between resilient and high-risk groups. Conclusion: FH+/resilient youth showed stronger synchrony between brain regions associated with cognitive control, particularly those associated with flexible adaptation of thoughts and behaviors. Although preliminary, the results of this study set the stage for a continued focus on risk-group heterogeneity to better identify neural markers of resilience against substance use problems in vulnerable populations.

PMID: 31368775 [PubMed - as supplied by publisher]

[Analysis on regional homogeneity of resting brain during balance acupuncture-induced analgesic effect in migraine patients without aura].

Fri, 08/02/2019 - 14:00
Related Articles

[Analysis on regional homogeneity of resting brain during balance acupuncture-induced analgesic effect in migraine patients without aura].

Zhen Ci Yan Jiu. 2019 Jun 25;44(6):446-50

Authors: Qin XL, Wang WY, Wang JZ, Xie WY, Zhang YM, Gao YQ

Abstract
OBJECTIVE: To observe the relationship between the analgesic effect of balance acupuncture and functional changes in brain in patients with migraine without aura.
METHODS: A total of 40 cases of migraine without aura were equally randomized into a headache-acupoint group and a sham-acupoint group. When acupuncture given, a filiform needle was inserted into the headache-acupoint (the midpoint of the depression region anterior to the juncture of the first and second metatarsal bones on the dorsum of the foot) or the sham point (the midpoint of the depression region anterior to the juncture site between the 3rd and 4th metatarsal joints of the dorsum of the foot) about 25-40 mm deep and manipulated for a while till the patient experienced feelings of electric shock and numbness, then withdrawn immediately. The treatment was conducted once daily for 4 weeks. The visual analogue scale (VAS) was used to evaluate the severity of pain, and the regional homogeneity (ReHo) analysis of resting state functional magnetic resonance imaging (fMRI) was used to assess changes of the spontaneous brain activity.
RESULTS: After acupuncture, the analgesic effect of headache-acupoint was better than that of the sham-acupoint in both intervention stage and the follow-up stage (P< 0.05), and was also stronger in the intervention stage than in the follow-up stage (P<0.05). There was no significant difference in the analgesic effect between the intervention stage and the follow-up stage in the sham-acupoint group (P>0.05). Compared with pre-intervention, 4-weeks' intervention at the headache-acupoint showed an increase of ReHo values in the anterior cingulate gyrus, anterior central gyrus, superior orbital frontal gyrus, insula, inferior lobule, left anterior cingulate gyrus, ventral lateral nucleus and ventral posteromedial nucleus of the thalamus, pontine nucleus, cerebellar tonsils and orbital frontal inferior gyrus of the brain (P<0.05), and a decrease of ReHo values in the right brain bridge, central posterior gyrus, posterior cingulate gyrus, left central anterior gyrus, posterolateral nucleus of thalamus, and hippocampus (P<0.05), separately. In the sham-acupoint group, the ReHo value was increased in the right tongue gyrus, the left anterior lobe, the anterior cingulate gyrus and the lower occipital gyrus of the brain (P<0.05), and reduced in the left ventral posterolateral nucleus of the thalamus, separately (P<0.05).
CONCLUSION: Balance acupuncture stimulation of headache acupoint has an analgesic effect in migraine patients without aura, which may be related to its effect in regulating resting state brain function of the limbic-system-dominated multiple brain regions.

PMID: 31368270 [PubMed - in process]

Effects of acupuncture on craving after tobacco cessation: a resting-state fMRI study based on the fractional amplitude of low-frequency fluctuation.

Fri, 08/02/2019 - 14:00
Related Articles

Effects of acupuncture on craving after tobacco cessation: a resting-state fMRI study based on the fractional amplitude of low-frequency fluctuation.

Quant Imaging Med Surg. 2019 Jun;9(6):1118-1125

Authors: Wang YY, Liu Z, Chen F, Sun L, Wu Y, Yang JS, Fang JL

Abstract
Background: To explore the immediate effects and mechanism of acupuncture on craving after tobacco cessation based on the fractional amplitude of low-frequency fluctuation (fALFF).
Methods: This was a functional magnetic resonance imaging (fMRI) study. Forty participants were recruited and divided into a smoking group and a non-smoking group, 20 cases in each one. The smoking participants were requested to quit smoking 24 hours before the fMRI scan. The scan process was scan - acupuncture - scan. Between the two scans, acupuncture was applied at Lieque (LU 7), Hegu (LI 4), Baihui (GV 20), Zusanli (ST 36), Sanyinjiao (SP 6) and Taichong (LR 3) in two groups.
Results: After acupuncture, self-made craving for smoking, Minnesota Nicotine Withdrawal Scale (MNWS) and Questionnaire of Smoking Urges (QSU) were all reduced (P<0.05). The fMRI results indicated the immediate effects of acupuncture on smoking craving were significant, and identified salience network (SN) consisted of anterior cingulate cortex and insula, prefrontal cortex, visual cortex and cerebellum as key brains area. Correlation analysis indicated that NWNS scores were positively correlated with the mean fALFF in the ACC (P<0.05) and negatively correlated with the mean fALFF in the insula (P<0.05) in the smoking group.
Conclusions: This was the first study in China to explore the neural mechanisms of acupuncture for smoking craving. The results indicated that the effects of acupuncture on smoking craving were significant, and the SN played a critical role in the process.

PMID: 31367566 [PubMed]

Functional Connectivity in Adult Brain Tumor Patients: A Systematic Review.

Fri, 08/02/2019 - 14:00
Related Articles

Functional Connectivity in Adult Brain Tumor Patients: A Systematic Review.

Brain Connect. 2018 09;8(7):381-397

Authors: Fox ME, King TZ

Abstract
Brain tumor (BT) patients often experience reduced cognitive abilities and disrupted adaptive functioning before and after treatment. An innovative approach to understanding the underlying brain networks associated with these outcomes has been to study the brain's functional connectivity (FC), the spatially distributed and temporally correlated activity throughout the brain, and how it can be affected by a tumor. The present review synthesized the extant BT FC literature that utilizes functional magnetic resonance imaging to study FC strength of commonly observed networks during rest and task. A systematic review of English articles using PubMed was conducted. Search terms included brain tumor OR glioma AND functional connectivity, independent component analysis, ICA, psychophysiological interaction, OR PPI. Studies in which participants were diagnosed with BTs as adults that evaluated specific networks of interest using independent component analysis or seed-based component analysis were included. Twenty-five studies met inclusion criteria. BT patients often presented with decreases in FC strength within well-established networks and increases in atypical FC patterns. Network differences were tumor adjacent and distal, and left hemisphere tumors generally had a greater impact on FC. FC alterations often correlated with behavioral or cognitive outcomes when assessed. Overall, BTs appear to lead to various alterations in FC across different functional networks, and the most common change is a decrease in expected FC strength. More longitudinal studies are needed to determine the time course of network alterations across treatment and recovery, the role of medical treatments in BT survivors' FC, and the potential of FC patterns as biomarkers of cognitive outcomes.

PMID: 30141339 [PubMed - indexed for MEDLINE]

A role for the CD38 rs3796863 polymorphism in alcohol and monetary reward: evidence from CD38 knockout mice and alcohol self-administration, [11C]-raclopride binding, and functional MRI in humans.

Thu, 08/01/2019 - 12:40
Related Articles

A role for the CD38 rs3796863 polymorphism in alcohol and monetary reward: evidence from CD38 knockout mice and alcohol self-administration, [11C]-raclopride binding, and functional MRI in humans.

Am J Drug Alcohol Abuse. 2019 Jul 31;:1-13

Authors: Lee MR, Shin JH, Deschaine S, Daurio AM, Stangl BL, Yan J, Ramchandani VA, Schwandt ML, Grodin EN, Momenan R, Corral-Frias NS, Hariri AR, Bogdan R, Alvarez VA, Leggio L

Abstract
Background: Cluster of differentiation 38 (CD38) is a transmembrane protein expressed in dopaminergic reward pathways in the brain, including the nucleus accumbens (NAc). The GG genotype of a common single nucleotide polymorphism (SNP) within CD38, rs3796863, is associated with increased social reward. Objective: Examine whether CD38 rs3796863 and Cd38 knockout (KO) are associated with reward-related neural and behavioral phenotypes. Methods: Data from four independent human studies were used to test whether rs3796863 genotype is associated with: (1) intravenous alcohol self-administration (n = 64, 30 females), (2) alcohol-stimulated dopamine (DA) release measured using 11C-raclopride positron emission tomography (n = 22 men), (3) ventral striatum (VS) response to positive feedback measured using a card guessing functional magnetic resonance imaging (fMRI) paradigm (n = 531, 276 females), and (4) resting state functional connectivity (rsfc) of the VS (n = 51, 26 females). In a fifth study, we used a mouse model to examine whether cd38 knockout influences stimulated DA release in the NAc core and dorsal striatum using fast-scanning cyclic voltammetry. Results: Relative to T allele carriers, G homozygotes at rs3796863 within CD38 were characterized by greater alcohol self-administration, alcohol-stimulated dopamine release, VS response to positive feedback, and rsfc between the VS and anterior cingulate cortex. High-frequency stimulation reduced DA release among Cd38 KO mice had reduced dopamine release in the NAc. Conclusion: Converging evidence suggests that CD38 rs3796863 genotype may increase DA-related reward response and alcohol consumption.

PMID: 31365285 [PubMed - as supplied by publisher]

Hippocampal atrophy and functional connectivity disruption in cirrhotic patients with minimal hepatic encephalopathy.

Thu, 08/01/2019 - 12:40
Related Articles

Hippocampal atrophy and functional connectivity disruption in cirrhotic patients with minimal hepatic encephalopathy.

Metab Brain Dis. 2019 Jul 30;:

Authors: Lin W, Chen X, Gao YQ, Yang ZT, Yang W, Chen HJ

Abstract
The hippocampus is a crucial pathological node for minimal hepatic encephalopathy (MHE) and it is associated with various cognitive impairments. Investigations on alterations involving hippocampal morphology and functional connectivity (FC) in MHE are limited. This study aimed to simultaneously evaluate hippocampal volume and FC alterations and their association with cognitive decline in MHE. Twenty-two cirrhotic patients with MHE, 31 cirrhotic patients without MHE (NHE), and 43 healthy controls underwent high-resolution T1-weighted imaging, resting-state functional magnetic resonance imaging, and cognition assessment based on Psychometric Hepatic Encephalopathy Score (PHES). The structural images were preprocessed using a voxel-based morphometry method, during which hippocampal volume was measured. The hippocampal connectivity network was identified using seed-based correlation analysis. Hippocampal volume and FC strength were compared across the three groups and correlated against the PHES results of the cirrhotic patients. Compared to the controls, MHE patients exhibited a significantly lower bilateral hippocampal volume. A slight decrease in hippocampal volume was obtained from NHE to MHE, but it did not reach statistically significance. In addition, the average FC strength of the bilateral hippocampal connectivity network was significantly lower in the MHE patients. In particular, the MHE patients showed a decrease in FC involving the left hippocampus to bilateral posterior cingulate gyrus and left angular gyrus. The MHE patients also showed FC reduction between the right hippocampus and bilateral medial frontal cortex. A progressive reduction in hippocampal FC from NHE to MHE was also observed. The bilateral hippocampal FC strength (but not hippocampal volume) was positively correlated with the PHES results of the cirrhotic patients. Our assessment of MHE patients revealed decreased hippocampal volume, which suggests regional atrophy, and reduced hippocampal connectivity with regions that are primarily involved in the default-mode network, thereby suggesting a functional disconnection syndrome. These alterations reveal the mechanisms underlying cognitive deterioration with disease progression.

PMID: 31363985 [PubMed - as supplied by publisher]

Incremental benefits of EEG informed fMRI in the study of disorders related to meso-corticolimbic dopamine pathway dysfunction: A systematic review of recent literature.

Thu, 08/01/2019 - 12:40
Related Articles

Incremental benefits of EEG informed fMRI in the study of disorders related to meso-corticolimbic dopamine pathway dysfunction: A systematic review of recent literature.

J Clin Neurosci. 2019 Jul;65:87-99

Authors: Syed Nasser N, Ibrahim B, Sharifat H, Abdul Rashid A, Suppiah S

Abstract
Functional magnetic resonance imaging (fMRI) is a non-invasive imaging modality that enables the assessment of neural connectivity and oxygen utility of the brain using blood oxygen level dependent (BOLD) imaging sequence. Electroencephalography (EEG), on the other hands, looks at cortical electrical impulses of the brain thus detecting brainwave patterns during rest and thought processing. The combination of these two modalities is called fMRI with simultaneous EEG (fMRI-EEG), which has emerged as a new tool for experimental neuroscience assessments and has been applied clinically in many settings, most commonly in epilepsy cases. Recent advances in imaging has led to fMRI-EEG being utilized in behavioural studies which can help in giving an objective assessment of ambiguous cases and help in the assessment of response to treatment by providing a non-invasive biomarker of the disease processes. We aim to review the role and interpretation of fMRI-EEG in studies pertaining to psychiatric disorders and behavioral abnormalities.

PMID: 30955950 [PubMed - indexed for MEDLINE]

White matter lesion loads associated with dynamic functional connectivity within attention network in patients with relapsing-remitting multiple sclerosis.

Thu, 08/01/2019 - 12:40
Related Articles

White matter lesion loads associated with dynamic functional connectivity within attention network in patients with relapsing-remitting multiple sclerosis.

J Clin Neurosci. 2019 Jul;65:59-65

Authors: Huang M, Zhou F, Wu L, Wang B, Guo L, Zhao Y, Wan H, Li F, Zeng X, Gong H

Abstract
Using time-variant of blood oxygenation level dependent (BOLD) signal to investigate the temporal changes in functional connectivity (FC) between key nodes may shed light on the dynamic characteristics of network. Twenty-two relapsing-remitting multiple sclerosis (RRMS) and 22 well-matched healthy control subjects (HCs) participated in this study. Previously validated key nodes of attention network seeds were defined as spherical regions of interests (ROIs); then, we captured the pattern of dFC using sliding window correlation of ROIs in the RRMS and HCs during rest. Furthermore, correlation analysis between altered dFC of paired-ROIs with clinical measures in RRMS were performed. Compared with the HCs, the RRMS showed: a certain specificity transient pattern of FC of attention network at time window levels, including decreased dFC within dorsal attention network [connections of left intraparietal sulcus (LIPS)-right intraparietal sulcus (RIPS), LIPS-right frontal eye field (RFEF) and left frontal eye field (LFEF)-RIPS] and ventral attention network [connection of right ventral frontal cortex (RVFC)-right temporal parietal junction (RTPJ)], increased dFC between dorsal and ventral attention network (connections of LIPS-RTPJ and LIPS-RVFC). Secondary analysis indicated that the dFC coefficients of the connections of LIPS-RIPS (r = -0.467, P = 0.023) and RVFC-RTPJ (r = -0.452, P = 0.043) were significant negative correlated with the total white matter lesion load. In conclusion, we found that the instantaneous configuration pattern of FC in attention network of RRMS are relate to lesions loads.

PMID: 30940453 [PubMed - indexed for MEDLINE]

The Big Reveal: Precision Mapping Shines a Gigantic Floodlight on the Cerebellum.

Thu, 08/01/2019 - 12:40
Related Articles

The Big Reveal: Precision Mapping Shines a Gigantic Floodlight on the Cerebellum.

Neuron. 2018 11 21;100(4):773-776

Authors: Fair DA

Abstract
The cerebellum, a brain structure historically considered to be important for motor coordination, is often overlooked in terms of its role in higher-order control processing. Using resting-state functional connectivity and precision mapping, Marek et al. (2018) illuminate the cerebellum as an important source of individual variation in brain function and cognition.

PMID: 30465762 [PubMed - indexed for MEDLINE]

Interpretable, highly accurate brain decoding of subtly distinct brain states from functional MRI using intrinsic functional networks and long short-term memory recurrent neural networks.

Wed, 07/31/2019 - 11:40
Related Articles

Interpretable, highly accurate brain decoding of subtly distinct brain states from functional MRI using intrinsic functional networks and long short-term memory recurrent neural networks.

Neuroimage. 2019 Jul 27;:116059

Authors: Li H, Fan Y

Abstract
Decoding brain functional states underlying cognitive processes from functional MRI (fMRI) data using multivariate pattern analysis (MVPA) techniques has achieved promising performance for characterizing brain activation patterns and providing neurofeedback signals. However, it remains challenging to decode subtly distinct brain states for individual fMRI data points due to varying temporal durations and dependency among different cognitive processes. In this study, we develop a deep learning based framework for brain decoding by leveraging recent advances in intrinsic functional network modeling and sequence modeling using long short-term memory (LSTM) recurrent neural networks (RNNs). Particularly, subject-specific intrinsic functional networks (FNs) are computed from resting state fMRI data and are used to characterize functional signals of task fMRI data with a compact representation for building brain decoding models, and LSTM RNNs are adopted to learn brain decoding mappings between functional profiles and brain states. Validation results on fMRI data from the HCP dataset have demonstrated that brain decoding models built on training data using the proposed method could learn discriminative latent feature representations and effectively distinguish subtly distinct working memory tasks of different subjects with significantly higher accuracy than conventional decoding models. Informative FNs of the brain decoding models identified as brain activation patterns of working memory tasks were largely consistent with the literature. The method also obtained promising decoding performance on motor and social cognition tasks. Our results suggest that LSTM RNNs in conjunction with FNs could build interpretable, highly accurate brain decoding models.

PMID: 31362049 [PubMed - as supplied by publisher]

Disrupted brain functional networks in drug-naïve children with attention deficit hyperactivity disorder assessed using graph theory analysis.

Wed, 07/31/2019 - 11:40
Related Articles

Disrupted brain functional networks in drug-naïve children with attention deficit hyperactivity disorder assessed using graph theory analysis.

Hum Brain Mapp. 2019 Jul 30;:

Authors: Chen Y, Huang X, Wu M, Li K, Hu X, Jiang P, Chen L, He N, Dai J, Wang S, He M, Guo L, Sweeney JA, Gong Q

Abstract
Neuroimaging studies have revealed functional brain network abnormalities in attention deficit hyperactivity disorder (ADHD), but the results have been inconsistent, potentially related to confounding medication effects. Furthermore, specific topological alterations in functional networks and their role in behavioral inhibition dysfunction remain to be established. Resting-state functional magnetic resonance imaging was performed on 51 drug-naïve children with ADHD and 55 age-matched healthy controls. Brain functional networks were constructed by thresholding the partial correlation matrices of 90 brain regions, and graph theory was used to analyze network topological properties. The Stroop test was used to assess cognitive inhibitory abilities. Nonparametric permutation tests were used to compare the topological architectures in the two groups. Compared with healthy subjects, brain networks in ADHD patients demonstrated altered topological characteristics, including lower global (FDR q = 0.01) and local efficiency (p = 0.032, uncorrected) and a longer path length (FDR q = 0.01). Lower nodal efficiencies were found in the left inferior frontal gyrus and anterior cingulate cortex in the ADHD group (FDR both q < 0.05). Altered global and nodal topological efficiencies were associated with the severity of inhibitory cognitive control deficits and hyperactivity symptoms in ADHD (p <0 .05). Alterations in network topologies in drug-naïve ADHD patients indicate weaker small-worldization with decreased segregation and integration of functional brain networks. Deficits in the cingulo-fronto-parietal attention network were associated with inhibitory control deficits.

PMID: 31361385 [PubMed - as supplied by publisher]

Altered Functional Brain Network Integration, Segregation, and Modularity in Infants Born Very Preterm at Term-Equivalent Age.

Wed, 07/31/2019 - 11:40
Related Articles

Altered Functional Brain Network Integration, Segregation, and Modularity in Infants Born Very Preterm at Term-Equivalent Age.

J Pediatr. 2019 Jul 26;:

Authors: Bouyssi-Kobar M, De Asis-Cruz J, Murnick J, Chang T, Limperopoulos C

Abstract
OBJECTIVES: To determine the functional network organization of the brain in infants born very preterm at term-equivalent age and to relate network alterations to known clinical risk factors for poor neurologic outcomes in prematurity.
STUDY DESIGN: Resting-state functional magnetic resonance imaging data from 66 infants born very preterm (gestational age <32 weeks and birth weight <1500 g) and 66 healthy neonates born at full term, acquired as part of a prospective, cross-sectional study, were compared at term age using graph theory. Features of resting-state networks, including integration, segregation, and modularity, were derived from correlated hemodynamic activity arising from 93 cortical and subcortical regions of interest and compared between groups.
RESULTS: Despite preserved small-world topology and modular organization, resting-state networks of infants born very preterm at term-equivalent age were less segregated and less integrated than those of infants born full term. Chronic respiratory illness (ie, bronchopulmonary dysplasia and the length of oxygen support) was associated with decreased global efficiency and increased path lengths (P < .05). In both cohorts, 4 functional modules with similar composition were observed (parietal/temporal, frontal, subcortical/limbic, and occipital). The density of connections in 3 of the 4 modules was decreased in the very preterm network (P < .01); however, in the occipital/visual cortex module, connectivity was increased in infants born very preterm relative to control infants (P < .0001).
CONCLUSIONS: Early exposure to the ex utero environment is associated with altered resting-state network functional organization in infants born very preterm at term-equivalent age, likely reflecting disrupted brain maturational processes.

PMID: 31358292 [PubMed - as supplied by publisher]

Cannabis induced increase in striatal glutamate associated with loss of functional corticostriatal connectivity.

Wed, 07/31/2019 - 11:40
Related Articles

Cannabis induced increase in striatal glutamate associated with loss of functional corticostriatal connectivity.

Eur Neuropsychopharmacol. 2019 12;29(2):247-256

Authors: Mason NL, Theunissen EL, Hutten NRPW, Tse DHY, Toennes SW, Stiers P, Ramaekers JG

Abstract
Cannabis is the most commonly used illicit drug and is known to alter state of consciousness and impair neurocognitive function. However, the mechanisms underlying these effects have yet to be fully elucidated. Rodent studies suggest that Δ9-tetrahydrocannabinol (THC) activates dopaminergic neurons in the limbic system, subsequently enhancing dopamine, which is implicated in the rewarding effects of cannabis. Additional evidence suggests that THC may act indirectly on dopamine firing by modulating GABA and glutamate release. This double-blind, placebo-controlled study assessed the acute influence of two doses of THC on brain kinetics of glutamate, GABA, and dopamine, in relation to behavioral outcomes, by using magnetic resonance spectroscopy and functional magnetic resonance imaging. Twenty occasional cannabis users received acute doses of cannabis (300 µg/kg THC) and placebo, in one of two dose regimes (full dose and divided dose), during two separate testing days. Administration of THC increased striatal glutamate concentrations, and dopamine as indicated by a reduction in functional connectivity (FC) between the nucleus accumbens (NAc) and cortical areas. Alterations in glutamate and FC were dose dependent and evident in the full dose group where THC serum concentrations exceeded 2 ng/ml at T-max. Average glutamate changes correlated strongly with FC alterations. Additionally, THC induced changes in FC correlated with feelings of subjective high and decreased performance on an attention task. Taken together, this suggests that THC elicits subjective and cognitive alterations via increased striatal dopaminergic activity and loss of corticostriatal connectivity, which is associated with an increase in striatal glutamate.

PMID: 30553697 [PubMed - indexed for MEDLINE]

The relationship between spatial configuration and functional connectivity of brain regions.

Wed, 07/31/2019 - 11:40
Related Articles

The relationship between spatial configuration and functional connectivity of brain regions.

Elife. 2018 02 16;7:

Authors: Bijsterbosch JD, Woolrich MW, Glasser MF, Robinson EC, Beckmann CF, Van Essen DC, Harrison SJ, Smith SM

Abstract
Brain connectivity is often considered in terms of the communication between functionally distinct brain regions. Many studies have investigated the extent to which patterns of coupling strength between multiple neural populations relates to behaviour. For example, studies have used 'functional connectivity fingerprints' to characterise individuals' brain activity. Here, we investigate the extent to which the exact spatial arrangement of cortical regions interacts with measures of brain connectivity. We find that the shape and exact location of brain regions interact strongly with the modelling of brain connectivity, and present evidence that the spatial arrangement of functional regions is strongly predictive of non-imaging measures of behaviour and lifestyle. We believe that, in many cases, cross-subject variations in the spatial configuration of functional brain regions are being interpreted as changes in functional connectivity. Therefore, a better understanding of these effects is important when interpreting the relationship between functional imaging data and cognitive traits.

PMID: 29451491 [PubMed - indexed for MEDLINE]

Functional brain network topology in parents who lost their only child in China: Post-traumatic stress disorder and sex effects.

Tue, 07/30/2019 - 10:20

Functional brain network topology in parents who lost their only child in China: Post-traumatic stress disorder and sex effects.

J Affect Disord. 2019 Jul 03;257:632-639

Authors: Luo Y, Qi R, Zhang L, Qing Z, Weng Y, Wang W, Zhang X, Shan H, Li L, Cao Z, Lu G

Abstract
BACKGROUND: Post-traumatic stress disorder (PTSD) is associated with disruption of the brain network topology; however, little is known about the topological changes and sex effects in PTSD patients following a unique trauma, the loss of an only child, in China.
METHODS: Fifty-one lost-only-child parents with PTSD, 93 lost-only-child non-PTSD parents (NPTSD), and 50 healthy subjects underwent resting-state functional MRI. The whole-brain functional network was constructed by thresholding partial correlation matrices of 90 brain regions. Group differences in the topological properties, the diagnosis-by-sex interaction, and the relationships between topological metrics and clinical variables were investigated.
RESULTS: Compared with healthy subjects, PTSD and NPTSD groups exhibited significantly shorter path lengths and higher nodal centralities in many brain regions across sexes; however, no significant difference was found between the PTSD and NPTSD groups. Additionally, the global topological metrics did not show any sex difference, whereas the nodal centralities in the left insula, right inferior frontal gyrus, and right posterior cingulate cortex differed significantly only in women, and the nodal centralities in the bilateral anterior cingulate cortices and left hippocampus were significantly different only in men. Furthermore, the nodal centralities of the right parahippocampus demonstrated significant diagnosis-by-sex interaction.
LIMITATION: Cross-sectional design of this study could not demonstrate the causality.
CONCLUSIONS: The parents who lost their only child exhibited a shift toward randomization and significant nodal topological alterations independent of PTSD effects. Additionally, sex differences were observed primarily in the topological properties at the nodal level, which may indicate a neurobiological contribution to the greater incidence of PTSD in females.

PMID: 31357160 [PubMed - as supplied by publisher]

Pages