New resting-state fMRI related studies at PubMed

The relevant resting-state brain activity of ecological microexpression recognition test (EMERT).

Wed, 12/23/2020 - 16:40
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The relevant resting-state brain activity of ecological microexpression recognition test (EMERT).

PLoS One. 2020;15(12):e0241681

Authors: Yin M, Zhang J, Shu D, Liu D

Abstract
Zhang, et al. (2017) established the ecological microexpression recognition test (EMERT), but it only used white models' expressions as microexpressions and backgrounds, and there was no research detecting its relevant brain activity. The current study used white, black and yellow models' expressions as microexpressions and backgrounds to improve the materials ecological validity of EMERT, and it used eyes-closed and eyes-open resting-state fMRI to detect relevant brain activity of EMERT for the first time. The results showed: (1) Two new recapitulative indexes of EMERT were adopted, such as microexpression M and microexpression SD. The participants could effectively identify almost all the microexpressions, and each microexpression type had a significantly background effect. The EMERT had good retest reliability and calibration validity. (2) ALFFs (Amplitude of Low-Frequency Fluctuations) in both eyes-closed and eyes-open resting-states and ALFFs-difference could predict microexpression M. The relevant brain areas of microexpression M were some frontal lobes, insula, cingulate cortex, hippocampus, parietal lobe, caudate nucleus, thalamus, amygdala, occipital lobe, fusiform, temporal lobe, cerebellum and vermis. (3) ALFFs in both eyes-closed and eyes-open resting-states and ALFFs-difference could predict microexpression SD, and the ALFFs-difference was more predictive. The relevant brain areas of microexpression SD were some frontal lobes, insula, cingulate cortex, cuneus, amygdala, fusiform, occipital lobe, parietal lobe, precuneus, caudate lobe, putamen lobe, thalamus, temporal lobe, cerebellum and vermis. (4) There were many similarities and some differences in the relevant brain areas between microexpression M and SD. All these brain areas can be trained to enhance ecological microexpression recognition ability.

PMID: 33351809 [PubMed - as supplied by publisher]

Brain Connectivity Abnormalities and Treatment-Induced Restorations in Patients with Cervical Dystonia.

Wed, 12/23/2020 - 16:40
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Brain Connectivity Abnormalities and Treatment-Induced Restorations in Patients with Cervical Dystonia.

Eur J Neurol. 2020 Dec 22;:

Authors: Feng L, Yin D, Wang X, Xu Y, Xiang Y, Teng F, Pan Y, Zhang X, Su J, Wang Z, Jin L

Abstract
BACKGROUND: The relationship between brain abnormalities and phenotypic characteristics in cervical dystonia (CD) patients has not been fully established, and little is known about the neuroplastic changes induced by botulinum toxin type-A (BoNT-A) treatment.
METHODS: We retrospectively screened 92 CD patients presenting with rotational torticollis and 45 healthy controls from our database. After clinical assessment, 92 patients underwent baseline MRI scanning followed by a single-dose injection of BoNT-A. Four weeks later, 76 out of 92 patients were re-evaluated with the Tsui scale for dystonia severity, and 33 out of 76 patients completed post-treatment MRI scanning. Data-driven global brain connectivity and regional homogeneity in tandem with seed-based connectivity analyses were used to examine the functional abnormalities in CD and longitudinal circuit alterations that scaled with clinical response to BoNT-A. Multiple regression models were employed for prediction analysis of treatment efficacy.
RESULTS: CD patients exhibited elevated baseline connectivity of right postcentral gyrus with the left dorsomedial prefrontal cortex and right caudate nucleus, which was associated with their symptom severity. BoNT-A reduced excessive functional connectivity between the sensorimotor cortex and right superior frontal gyrus, which was significantly correlated with changes in Tsui score. Moreover, pre-treatment regional homogeneity of the left middle frontal gyrus was linearly related to varied response to treatment.
CONCLUSIONS: Our findings unravel dissociable connectivity of sensorimotor cortex underlying the pathology of CD and central effects of BoNT-A therapy. Furthermore, baseline regional homogeneity with left middle frontal gyrus may represent a potential evidence-based marker of patient stratification for BoNT-A therapy in CD.

PMID: 33350546 [PubMed - as supplied by publisher]

Whole-Brain Dynamics in Aging: Disruptions in Functional Connectivity and the Role of the Rich Club.

Wed, 12/23/2020 - 16:40
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Whole-Brain Dynamics in Aging: Disruptions in Functional Connectivity and the Role of the Rich Club.

Cereb Cortex. 2020 Dec 22;:

Authors: Escrichs A, Biarnes C, Garre-Olmo J, Fernández-Real JM, Ramos R, Pamplona R, Brugada R, Serena J, Ramió-Torrentà L, Coll-De-Tuero G, Gallart L, Barretina J, Vilanova JC, Mayneris-Perxachs J, Essig M, Figley CR, Pedraza S, Puig J, Deco G

Abstract
Normal aging causes disruptions in the brain that can lead to cognitive decline. Resting-state functional magnetic resonance imaging studies have found significant age-related alterations in functional connectivity across various networks. Nevertheless, most of the studies have focused mainly on static functional connectivity. Studying the dynamics of resting-state brain activity across the whole-brain functional network can provide a better characterization of age-related changes. Here, we employed two data-driven whole-brain approaches based on the phase synchronization of blood-oxygen-level-dependent signals to analyze resting-state fMRI data from 620 subjects divided into two groups (middle-age group (n = 310); age range, 50-64 years versus older group (n = 310); age range, 65-91 years). Applying the intrinsic-ignition framework to assess the effect of spontaneous local activation events on local-global integration, we found that the older group showed higher intrinsic ignition across the whole-brain functional network, but lower metastability. Using Leading Eigenvector Dynamics Analysis, we found that the older group showed reduced ability to access a metastable substate that closely overlaps with the so-called rich club. These findings suggest that functional whole-brain dynamics are altered in aging, probably due to a deficiency in a metastable substate that is key for efficient global communication in the brain.

PMID: 33350451 [PubMed - as supplied by publisher]

Connectome-Based Prediction of Optimal Weight Loss Six Months After Bariatric Surgery.

Wed, 12/23/2020 - 16:40
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Connectome-Based Prediction of Optimal Weight Loss Six Months After Bariatric Surgery.

Cereb Cortex. 2020 Dec 22;:

Authors: Zhang W, Ji G, Manza P, Li G, Hu Y, Wang J, Lv G, He Y, von Deneen KM, Han Y, Cui G, Tomasi D, Volkow ND, Nie Y, Wang GJ, Zhang Y

Abstract
Despite bariatric surgery being the most effective treatment for obesity, a proportion of subjects have suboptimal weight loss post-surgery. Therefore, it is necessary to understand the mechanisms behind the variance in weight loss and identify specific baseline biomarkers to predict optimal weight loss. Here, we employed functional magnetic resonance imaging (fMRI) with baseline whole-brain resting-state functional connectivity (RSFC) and a multivariate prediction framework integrating feature selection, feature transformation, and classification to prospectively identify obese patients that exhibited optimal weight loss at 6 months post-surgery. Siamese network, which is a multivariate machine learning method suitable for small sample analysis, and K-nearest neighbor (KNN) were cascaded as the classifier (Siamese-KNN). In the leave-one-out cross-validation, the Siamese-KNN achieved an accuracy of 83.78%, which was substantially higher than results from traditional classifiers. RSFC patterns contributing to the prediction consisted of brain networks related to salience, reward, self-referential, and cognitive processing. Further RSFC feature analysis indicated that the connection strength between frontal and parietal cortices was stronger in the optimal versus the suboptimal weight loss group. These findings show that specific RSFC patterns could be used as neuroimaging biomarkers to predict individual weight loss post-surgery and assist in personalized diagnosis for treatment of obesity.

PMID: 33350441 [PubMed - as supplied by publisher]

Altered habenula resting state functional connectivity in deprived veteran tobacco smokers: A pilot study.

Wed, 12/23/2020 - 16:40
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Altered habenula resting state functional connectivity in deprived veteran tobacco smokers: A pilot study.

Bull Menninger Clin. 2020;84(1):21-34

Authors: Jennings C, Gosnell S, Curtis KN, Kosten T, Salas R

Abstract
This study aimed to examine habenular resting state functional connectivity (RSFC) abnormalities in tobacco-smoking veterans. The authors explored RSFC in sated smokers (n = 3D 18), overnight deprived smokers (n = 3D 13), and nonsmoker controls (n = 3D 26). Seed-to-voxel analysis was used to explore RSFC in the habenula. Compared to sated smokers, deprived smokers demonstrated higher RSFC between the right habenula and two clusters of voxels: one in the right fusiform gyrus, and one in the left lingual gyrus. To study nicotine withdrawal, the authors used the Shiffman-Jarvik Withdrawal Questionnaire (SJWQ) score as a regressor and found higher RSFC between the right habenula and the left frontal pole in deprived compared to sated smokers. Right habenula RSFC distinguished between sated and deprived smokers and differentiated between sated and deprived smokers when using SJWQ as a regressor, suggesting a habenular role in tobacco withdrawal.

PMID: 31939683 [PubMed - indexed for MEDLINE]

[Alterations of regional homogeneity in patients with psychogenic erectile dysfunction: A study by resting-state functional MRI].

Tue, 12/22/2020 - 15:20
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[Alterations of regional homogeneity in patients with psychogenic erectile dysfunction: A study by resting-state functional MRI].

Zhonghua Nan Ke Xue. 2020 Feb;26(2):118-122

Authors: Yin T, Ren FQ, Ma ZY, Huang XP, Chang DG, Zhang PH

Abstract
Objective: To study the correlation between the brain regional homogeneity (ReHo) features and the clinical characteristics of the patients with psychogenic erectile dysfunction (pED).
METHODS: Using IIEF-5 and the Self-Esteem and Relationship (SEAR) questionnaire, we evaluated the erectile function and psychosocial status of 32 pED patients and 28 healthy male subjects. Then, we compared the regional brain activity between the patients and healthy controls by resting-state functional magnetic resonance imaging (RS-fMRI) and the ReHo method, analyzed the correlation of the ReHo value of the altered brain regions with the results of IIEF-5 and SEAR questionnaire investigation, and explored the relationship between the ReHo features and the symptoms of the pED patients.
RESULTS: Compared with the healthy male subjects, the pED patients obtained significantly lower IIEF-5 scores (22.21 ± 0.98 vs 13.97 ± 3.60, P < 0.01) and SEAR scores (61.92 ± 3.73 vs 37.58 ± 7.96, P < 0.01), a higher ReHo value of the left lateral cerebellum, and a lower ReHo value of the right precentral gyrus. The ReHo value of the left lateral cerebellum was correlated negatively with the IIEF-5 scores (r= -0.51, P < 0.01) and SEAR scores (r = -0.54, P < 0.01), while that of the right precentral gyrus positively with the IIEF-5 scores (r = 0.57, P < 0.01) and SEAR scores (r = 0.66, P < 0.01).
CONCLUSIONS: Patients with pED had lateral cerebellum-mediated abnormal sensory integration and precentral gyrus-related dysfunction of motor imagery and motor execution.

PMID: 33346413 [PubMed - in process]

Perinidal Angiogenesis Is a Predictor for Neurovascular Uncoupling in the Periphery of Brain Arteriovenous Malformations: A Task-Based and Resting-State fMRI Study.

Tue, 12/22/2020 - 15:20
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Perinidal Angiogenesis Is a Predictor for Neurovascular Uncoupling in the Periphery of Brain Arteriovenous Malformations: A Task-Based and Resting-State fMRI Study.

J Magn Reson Imaging. 2020 Dec 21;:

Authors: Li M, Liu Q, Guo R, Yang S, Jiang P, Chen X, Wu J, Cao Y, Wang S

Abstract
BACKGROUND: Potential neurovascular uncoupling (NVU) related to perinidal angiogenesis (PA) of brain arteriovenous malformations (AVMs) may cause inappropriate presurgical mapping using functional magnetic resonance imaging (fMRI), resulting in overconfident resection and postoperative morbidity.
PURPOSE: To evaluate the potential impact of PA upon fMRI blood oxygen level-dependent signal in the periphery of AVMs.
STUDY TYPE: Prospective.
POPULATION: Twenty-one patients with AVMs located in the primary sensorimotor cortex (SM1) undergoing task-based fMRI (hand motor), and 19 patients with supratentorial AVMs undergoing resting-state fMRI.
FIELD STRENGTH/SEQUENCE: 3.0T, echo-planar, time-of-flight, and magnetization-prepared rapid gradient-echo.
ASSESSMENT: The presence of PA was determined by three observers (Y.C., J.W., and X.C.) according to digital subtraction angiography and MR angiography. Interhemispheric asymmetry of fMRI activations contralateral to hand movements was evaluated with the interhemispheric ratio of the average t-value within ipsilesional SM1 to contralesional SM1. Regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuations (fALFF) were extracted from ring-shaped perinidal regions and contralateral homologous regions, and the corresponding interhemispheric ratios were calculated. The effect of PA on the interhemispheric asymmetry of motor activations, ReHo, and fALFF was estimated.
STATISTICAL TESTS: Pearson analysis, paired and independent t-test, multiple linear regression, Friedman test, and factorial analysis of variance were used.
RESULTS: Motor activations were significantly reduced in ipsilesional SM1 compared to contralesional SM1 (P < 0.05). The presence of PA was the independent predictor of activation loss in ipsilateral SM1(P < 0.05). Furthermore, perinidal regions exhibited reduced ReHo compared to the homologous regions (P < 0.05). PA was significantly associated with the decline of ReHo and fALFF in perinidal regions (P < 0.05, for both).
DATA CONCLUSION: The presence of PA can predict perinidal NVU that may confound the interpretation of both task-based and resting-state fMRI, highlighting the importance of alternative approaches of brain functional localization in improving treatment of AVMs.
LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

PMID: 33345355 [PubMed - as supplied by publisher]

Hormonal contraceptive phases matter: Resting-state functional connectivity of emotion-processing regions under stress.

Tue, 12/22/2020 - 15:20
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Hormonal contraceptive phases matter: Resting-state functional connectivity of emotion-processing regions under stress.

Neurobiol Stress. 2020 Nov;13:100276

Authors: Nasseri P, Herrera AY, Gillette K, Faude S, White JD, Velasco R, Mather M

Abstract
Hormonal contraceptives (HCs) affect various processes related to emotion processing, including emotional memory, fear extinction, and the cortisol response to stress. Despite the modulating role of HCs on the stress response in women and variance in synthetic hormone levels across the HC cycle, little is known about the phase-related effects of HCs on the brain's response to stress. We investigated the effect of HC cycle phase on functional connectivity of memory- and emotion-related regions at rest after exposure to a stressor. Twenty HC users completed two sessions of resting-state functional magnetic resonance imaging after exposure to the cold pressor test, one during the hormone-present HC phase (when synthetic hormones are taken) and one during the hormone-absent HC phase (when synthetic hormones are not taken). Women showed higher functional connectivity between left amygdala and ventromedial prefrontal cortex during the hormone-present phase. During the hormone-absent phase, women showed higher coupling between left parahippocampus and right superior lateral occipital cortex. Our results suggest that the synthetic hormones contained in HCs may protect against the negative effects of stress on functional connectivity of emotional processing regions.

PMID: 33344729 [PubMed]

Dynamic Functional Connectivity as a complex random walk: Definitions and the dFCwalk toolbox.

Tue, 12/22/2020 - 15:20
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Dynamic Functional Connectivity as a complex random walk: Definitions and the dFCwalk toolbox.

MethodsX. 2020;7:101168

Authors: Arbabyazd LM, Lombardo D, Blin O, Didic M, Battaglia D, Jirsa V

Abstract
•We have developed a framework to describe the dynamics of Functional Connectivity (dFC) estimated from brain activity time-series as a complex random walk in the space of possible functional networks. This conceptual and methodological framework considers dFC as a smooth reconfiguration process, combining "liquid" and "coordinated" aspects. Unlike other previous approaches, our method does not require the explicit extraction of discrete connectivity states.•In our previous work, we introduced several metrics for the quantitative characterization of the dFC random walk. First, dFC speed analyses extract the distribution of the time-resolved rate of reconfiguration of FC along time. These distributions have a clear peak (typical dFC speed, that can already serve as a biomarker) and fat tails (denoting deviations from Gaussianity that can be detected by suitable scaling analyses of FC network streams). Second, meta-connectivity (MC) analyses identify groups of functional links whose fluctuations co-vary in time and that define veritable dFC modules organized along specific dFC meta-hub controllers (differing from conventional FC modules and hubs). The decomposition of whole-brain dFC by MC allows performing dFC speed analyses separately for each of the detected dFC modules.•We present here blocks and pipelines for dFC random walk analyses that are made easily available through a dedicated MATLABⓇ toolbox (dFCwalk), openly downloadable. Although we applied such analyses mostly to fMRI resting state data, in principle our methods can be extended to any type of neural activity (from Local Field Potentials to EEG, MEG, fNIRS, etc.) or even non-neural time-series.

PMID: 33344179 [PubMed]

Interaction Between Smoking and Internet Gaming Disorder on Spontaneous Brain Activity.

Tue, 12/22/2020 - 15:20
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Interaction Between Smoking and Internet Gaming Disorder on Spontaneous Brain Activity.

Front Psychiatry. 2020;11:586114

Authors: Qiu X, Han X, Wang Y, Ding W, Sun Y, Zhou Y, Lei H, Lin F

Abstract
Converging lines of evidence indicates that smoking and internet gaming disorder (IGD) affect spontaneous brain activity, respectively. However, little is known about whether these two factors work together on the human brain. In this study, we investigated the interaction between smoking and IGD on local spontaneous brain activity using amplitude of low-frequency fluctuation (ALFF) based on resting-state fMRI (rs-fMRI). Forty-six cigarette smokers, 38 IGD individuals, 34 participants with both IGD and cigarette smoking (IGD-Smoking), and 60 healthy individuals involved in the study. Voxel-wise analysis of covariance of ALFF revealed that there were significant interactions between IGD by smoking in the right medial pre-frontal cortex (MPFC)/ventral striatum, bilateral cerebellar, and visual-related regions as well as the left temporal gyrus. In the right MPFC/ventral striatum and left temporal gyrus, ALFF in smoking group was significantly higher than healthy group while there were no significant ALFF differences between IGD-Smoking group and IGD group. While in the bilateral cerebellar and visual-related regions, ALFF in the smoking group was significantly lower than healthy group while ALFF in IGD-Smoking group did not show significant difference with IGD group. In addition, in the smoking group, ALFF of the right MPFC/ventral striatum was associated positively with anxiety and depression scores while the ALFF value in the smoking group had a trend toward negative correlation with SDS scores in the bilateral cerebellar and visual-related regions. The ALFF value in the smoking group was associated positively with anxiety score in the left temporal gyrus. These findings indicate that smoking and IGD interacted with each other in the human brain. Our results, in terms of spontaneous brain activity, may imply the fact that IGD people are more tended to get smoking. Moreover, it is possible to predict that smokers may be more easily to get internet addiction than healthy people.

PMID: 33343420 [PubMed]

Aberrant Amplitude of Low-Frequency Fluctuations in Different Frequency Bands in Patients With Parkinson's Disease.

Tue, 12/22/2020 - 15:20
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Aberrant Amplitude of Low-Frequency Fluctuations in Different Frequency Bands in Patients With Parkinson's Disease.

Front Aging Neurosci. 2020;12:576682

Authors: Wang Z, Liu Y, Ruan X, Li Y, Li E, Zhang G, Li M, Wei X

Abstract
Previous studies reported abnormal spontaneous neural activity in Parkinson's disease (PD) patients using resting-state functional magnetic resonance imaging (R-fMRI). However, the frequency-dependent neural activity in PD is largely unknown. Here, 35 PD patients and 35 age- and education-matched healthy controls (HCs) underwent R-fMRI scanning to investigate abnormal spontaneous neural activity of PD using the amplitude of low-frequency fluctuation (ALFF) approach within the conventional band (typical band: 0.01-0.08 Hz) and specific frequency bands (slow-5: 0.010-0.027 Hz and slow-4: 0.027-0.073 Hz). Compared with HCs, PD patients exhibited increased ALFF in the parieto-temporo-occipital regions, such as the bilateral inferior temporal gyrus/fusiform gyrus (ITG/FG) and left angular gyrus/posterior middle temporal gyrus (AG/pMTG), and displayed decreased ALFF in the left cerebellum, right precuneus, and left postcentral gyrus/supramarginal gyrus (PostC/SMG) in the typical band. PD patients showed greater increased ALFF in the left caudate/putamen, left anterior cingulate cortex/medial superior frontal gyrus (ACC/mSFG), left middle cingulate cortex (MCC), right ITG, and left hippocampus, along with greater decreased ALFF in the left pallidum in the slow-5 band, whereas greater increased ALFF in the left ITG/FG/hippocampus accompanied by greater decreased ALFF in the precentral gyrus/PostC was found in the slow-4 band (uncorrected). Additionally, the left caudate/putamen was positively correlated with levodopa equivalent daily dose (LEDD), Hoehn and Yahr (HY) stage, and disease duration. Our results suggest that PD is related to widespread abnormal brain activities and that the abnormalities of ALFF in PD are associated with specific frequency bands. Future studies should take frequency band effects into account when examining spontaneous neural activity in PD.

PMID: 33343329 [PubMed]

Gray Matter Volume and Functional Connectivity in Hypochondriasis: A Magnetic Resonance Imaging and Support Vector Machine Analysis.

Tue, 12/22/2020 - 15:20
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Gray Matter Volume and Functional Connectivity in Hypochondriasis: A Magnetic Resonance Imaging and Support Vector Machine Analysis.

Front Hum Neurosci. 2020;14:596157

Authors: Shen Z, Yu L, Zhao Z, Jin K, Pan F, Hu S, Li S, Xu Y, Xu D, Huang M

Abstract
Objective: Patients with hypochondriasis hold unexplainable beliefs and a fear of having a lethal disease, with poor compliances and treatment response to psychotropic drugs. Although several studies have demonstrated that patients with hypochondriasis demonstrate abnormalities in brain structure and function, gray matter volume (GMV) and functional connectivity (FC) in hypochondriasis still remain unclear. Methods: The present study collected T1-weighted and resting-state functional magnetic resonance images from 21 hypochondriasis patients and 22 well-matched healthy controls (HCs). We first analyzed the difference in the GMV between the two groups. We then used the regions showing a difference in GMV between two groups as seeds to perform functional connectivity (FC) analysis. Finally, a support vector machine (SVM) was applied to the imaging data to distinguish hypochondriasis patients from HCs. Results: Compared with the HCs, the hypochondriasis group showed decreased GMV in the left precuneus, and increased GMV in the left medial frontal gyrus. FC analyses revealed decreased FC between the left medial frontal gyrus and cuneus, and between the left precuneus and cuneus. A combination of both GMV and FC in the left precuneus, medial frontal gyrus, and cuneus was able to discriminate the hypochondriasis patients from HCs with a sensitivity of 0.98, specificity of 0.93, and accuracy of 0.95. Conclusion: Our study suggests that smaller left precuneus volumes and decreased FC between the left precuneus and cuneus seem to play an important role of hypochondriasis. Future studies are needed to confirm whether this finding is generalizable to patients with hypochondriasis.

PMID: 33343319 [PubMed]

Altered Functional Connectivity in White and Gray Matter in Patients With Multiple Sclerosis.

Tue, 12/22/2020 - 15:20
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Altered Functional Connectivity in White and Gray Matter in Patients With Multiple Sclerosis.

Front Hum Neurosci. 2020;14:563048

Authors: Huang J, Li M, Li Q, Yang Z, Xin B, Qi Z, Liu Z, Dong H, Li K, Ding Z, Lu J

Abstract
Background: Functional magnetic resonance imaging (fMRI) has been widely used to assess neural activity changes in gray matter (GM) in patients with multiple sclerosis (MS); however, brain function alterations in white matter (WM) relatively remain under-explored. Purpose: This work aims to identify the functional connectivity in both the WM and the GM of patients with MS using fMRI and the correlations between these functional changes and cumulative disability as well as the lesion ratio. Materials and Methods: For this retrospective study, 37 patients with clinically definite MS and 43 age-matched healthy controls were included between 2010 and 2014. Resting-state fMRI was performed. The WFU Pick and JHU Eve atlases were used to define 82 GM and 48 WM regions in common spaces, respectively. The time courses of blood oxygen level-dependent (BOLD) signals were averaged over each GM or WM region. The averaged time courses for each pair of GM and WM regions were correlated. All 82 × 48 correlations for each subject formed a functional correlation matrix. Results: Compared with the healthy controls, the MS patients had a decreased temporal correlation between the WM and the GM regions. Five WM bundles and four GM regions had significantly decreased mean correlation coefficients (CCs). More specifically, the WM functional alterations were negatively correlated with the lesion volume in the bilateral fornix, and the mean GM-averaged CCs of the WM bundles were inversely correlated with the lesion ratio (r = -0.36, P = 0.012). No significant correlation was found between WM functional alterations and the paced auditory serial addition test score, Expanded Disease Severity Scale score, and Multiple Sclerosis Severity Score (MSSS) in MS. Conclusions: These findings highlight current gaps in our knowledge of the WM functional alterations in patients with MS and may link WM function with pathological mechanisms.

PMID: 33343314 [PubMed]

Amplitude of fNIRS Resting-State Global Signal Is Related to EEG Vigilance Measures: A Simultaneous fNIRS and EEG Study.

Tue, 12/22/2020 - 15:20
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Amplitude of fNIRS Resting-State Global Signal Is Related to EEG Vigilance Measures: A Simultaneous fNIRS and EEG Study.

Front Neurosci. 2020;14:560878

Authors: Chen Y, Tang J, Chen Y, Farrand J, Craft MA, Carlson BW, Yuan H

Abstract
Recently, functional near-infrared spectroscopy (fNIRS) has been utilized to image the hemodynamic activities and connectivity in the human brain. With the advantage of economic efficiency, portability, and fewer physical constraints, fNIRS enables studying of the human brain at versatile environment and various body positions, including at bed side and during exercise, which complements the use of functional magnetic resonance imaging (fMRI). However, like fMRI, fNIRS imaging can be influenced by the presence of a strong global component. Yet, the nature of the global signal in fNIRS has not been established. In this study, we investigated the relationship between fNIRS global signal and electroencephalogram (EEG) vigilance using simultaneous recordings in resting healthy subjects in high-density and whole-head montage. In Experiment 1, data were acquired at supine, sitting, and standing positions. Results found that the factor of body positions significantly affected the amplitude of the resting-state fNIRS global signal, prominently in the frequency range of 0.05-0.1 Hz but not in the very low frequency range of less than 0.05 Hz. As a control, the task-induced fNIRS or EEG responses to auditory stimuli did not differ across body positions. However, EEG vigilance plays a modulatory role in the fNIRS signals in the frequency range of less than 0.05 Hz: resting-state sessions of low EEG vigilance measures are associated with high amplitudes of fNIRS global signals. Moreover, in Experiment 2, we further examined the epoch-to-epoch fluctuations in concurrent fNIRS and EEG data acquired from a separate group of subjects and found a negative temporal correlation between EEG vigilance measures and fNIRS global signal amplitudes. Our study for the first time revealed that vigilance as a neurophysiological factor modulates the resting-state dynamics of fNIRS, which have important implications for understanding and processing the noises in fNIRS signals.

PMID: 33343275 [PubMed]

Effect of different motor skills training on motor control network in the frontal lobe and basal ganglia.

Tue, 12/22/2020 - 15:20
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Effect of different motor skills training on motor control network in the frontal lobe and basal ganglia.

Biol Sport. 2020 Dec;37(4):405-413

Authors: Shi J, Wang J, Lang J, Zhang Z, Bi Y, Liu R, Jiang S, Hou L

Abstract
During human motor control, the three pathways of motor control coordinate to complete human response and inhibition control, so whether different types of motor skills training will affect the three pathways of motor control is the main question in this study. Magnetic resonance imaging was combined with behavioural evaluation to analyse the effects of different special training sessions on the motor control network of the frontal lobe and basal ganglia and to explore the role of the central nervous system in the regulation of motor behaviour. A Stop-signal paradigm was used to measure reaction and inhibition capacity, functional magnetic resonance imaging was used for whole brain scanning, and resting state data were collected. Compared to the control group, the competitive aerobics athletes had better reflexes while the soccer players had both better reflexes and inhibitory control. Furthermore, we found that training in the two sets of skills resulted in significant differences in different resting state brain function parameters compared with the control group. Additionally, there were significant differences among the three groups in the direct and indirect pathways of motor control in terms of functional connectivity. Open skill training may improve reaction ability while closed skill training improve both reaction and inhibition ability. These results suggest that the strength of the functional connectivity between the right inferior frontal gyrus and the left putamen may be a key to improving the inhibitory, and the left supplementary motor area- bilateral thalamic loop may play an inhibitory role in motor control.

PMID: 33343074 [PubMed]

The M1/M4 preferring muscarinic agonist xanomeline modulates functional connectivity and NMDAR antagonist-induced changes in the mouse brain.

Tue, 12/22/2020 - 15:20
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The M1/M4 preferring muscarinic agonist xanomeline modulates functional connectivity and NMDAR antagonist-induced changes in the mouse brain.

Neuropsychopharmacology. 2020 Dec 20;:

Authors: Montani C, Canella C, Schwarz AJ, Li J, Gilmour G, Galbusera A, Wafford K, Gutierrez-Barragan D, McCarthy A, Shaw D, Knitowski K, McKinzie D, Gozzi A, Felder C

Abstract
Cholinergic drugs acting at M1/M4 muscarinic receptors hold promise for the treatment of symptoms associated with brain disorders characterized by cognitive impairment, mood disturbances, or psychosis, such as Alzheimer's disease or schizophrenia. However, the brain-wide functional substrates engaged by muscarinic agonists remain poorly understood. Here we used a combination of pharmacological fMRI (phMRI), resting-state fMRI (rsfMRI), and resting-state quantitative EEG (qEEG) to investigate the effects of a behaviorally active dose of the M1/M4-preferring muscarinic agonist xanomeline on brain functional activity in the rodent brain. We investigated both the effects of xanomeline per se and its modulatory effects on signals elicited by the NMDA-receptor antagonists phencyclidine (PCP) and ketamine. We found that xanomeline induces robust and widespread BOLD signal phMRI amplitude increases and decreased high-frequency qEEG spectral activity. rsfMRI mapping in the mouse revealed that xanomeline robustly decreased neocortical and striatal connectivity but induces focal increases in functional connectivity within the nucleus accumbens and basal forebrain. Notably, xanomeline pre-administration robustly attenuated both the cortico-limbic phMRI response and the fronto-hippocampal hyper-connectivity induced by PCP, enhanced PCP-modulated functional connectivity locally within the nucleus accumbens and basal forebrain, and reversed the gamma and high-frequency qEEG power increases induced by ketamine. Collectively, these results show that xanomeline robustly induces both cholinergic-like neocortical activation and desynchronization of functional networks in the mammalian brain. These effects could serve as a translatable biomarker for future clinical investigations of muscarinic agents, and bear mechanistic relevance for the putative therapeutic effect of these class of compounds in brain disorders.

PMID: 33342996 [PubMed - as supplied by publisher]

The effects of the functional interplay between the Default Mode and Executive Control Resting State Networks on cognitive outcome in preterm born infants at 6 months of age.

Mon, 12/21/2020 - 13:40
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The effects of the functional interplay between the Default Mode and Executive Control Resting State Networks on cognitive outcome in preterm born infants at 6 months of age.

Brain Cogn. 2020 Dec 17;147:105669

Authors: Della Rosa PA, Canini M, Marchetta E, Cirillo S, Pontesilli S, Scotti R, Natali Sora MG, Poloniato A, Barera G, Falini A, Scifo P, Baldoli C

Abstract
Preterm birth can affect cognitive functions, such as attention or more generally executive control mechanisms, with severity in impairments proportional to prematurity. The functional cross-talk between the Default Mode (DMN) and Executive Control (ECN) networks mirrors the integrity of cognitive processing and is directly related to brain development. In this study, a cohort of 20 preterm-born infants was investigated using rs-fMRI. First, we addressed biological maturity of the DMN per se and its interplay with the ECN in terms of patterns of increased functional connectivity. Second, we assessed the impact of the degree of prematurity on the DMN-ECN functional interplay development in relation to cognitive outcome at six months. Our results highlighted the emergence of DMN in preterm neonates, with connectivity strength and synchronization between the anterior DMN hub and frontal areas increasing as a function of biological maturity. Further, cognitive scores at 6 months were predicted by mPFC-ECN connectivity strength with degree of prematurity impacting on mPFC-ECN connectivity and triggering differential patterns of functional maturation of the ECN for very early/early and moderate/late preterm neonates. Our findings suggest that the prematurity window allows to observe precursors of functional plasticity that may underlie different developmental trajectories in preterm children.

PMID: 33341657 [PubMed - as supplied by publisher]

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