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Obesogenic Diet-Associated C-Reactive Protein Predicts Reduced Central Dopamine and Corticostriatal Functional Connectivity in Female Rhesus Monkeys.

Fri, 04/03/2020 - 21:45
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Obesogenic Diet-Associated C-Reactive Protein Predicts Reduced Central Dopamine and Corticostriatal Functional Connectivity in Female Rhesus Monkeys.

Brain Behav Immun. 2020 Mar 30;:

Authors: Godfrey JR, Pincus M, Kovacs-Balint Z, Feczko E, Earl E, Miranda-Dominguez O, Fair DA, Jones SR, Locke J, Sanchez MM, Wilson ME, Michopoulos V

Abstract
Alterations in dopamine (DA) signaling and reductions in functional connectivity (FC; a measure of temporal correlations of activity between different brain regions) within dopaminergic reward pathways are implicated in the etiology of psychopathology and have been associated with increased concentrations of inflammatory markers, including C-reactive protein. Peripheral and central inflammatory cytokines that have been shown to disrupt DA signaling and corticostriatal FC are associated with C-reactive protein, an acute phase reactant that is used translationally as a marker of systemic inflammation. One factor that can significantly increase systemic inflammation to produce neuroadaptations in reward pathways is a diet that results in fat mass accumulation (e.g. obesogenic diet). The current study in female rhesus monkeys maintained in a standard laboratory chow (n=18) or on obesogenic diet (n=16) for 12-months tested the hypothesis that an obesogenic diet would alter central DA and homovanillic acid (HVA) concentrations, and be associated with increased CRP concentrations and decreased FC between corticostriatal regions at 12-months following dietary intervention. We specifically assessed FC between the nucleus accumbens (NAcc) and two sub-regions of the prefrontal cortex (PFC) previously associated with CRP concentrations, the ventromedial PFC (vmPFC) and the orbitofrontal cortex (OFC), which are also involved in emotional and motivational salience assessment, and in goal-directed behavior, impulse control and the salience/value of food, respectively. Results showed that CSF DA concentrations were decreased (p=0.002), HVA:DA ratios were increased (p=0.016), and body mass index was increased (p=0.047) over the 12-months of consuming an obesogenic diet. At 12-months, females maintained in the obesogenic diet exhibited higher CRP concentrations than females consuming chow-only (p=0.008). Linear regression analyses revealed significant CRP by dietary condition interactions on DA concentrations (β=-5.10; p=0.017) and HVA:DA ratios (β=5.14; p=0.029). Higher CRP concentrations were associated with lower CSF DA concentrations (r=-0.69; p=0.004) and greater HVA:DA ratios only in females maintained in the obesogenic dietary condition (r=0.58; p=0.024). Resting-state magnetic resonance neuroimaging (rs-fMRI) in a subset of females from each diet condition (n=8) at 12-months showed that higher CRP concentrations were associated decreased FC between the NAcc and subregions of the prefrontal cortex (PFC; p's<0.05). Decreased FC between the NAcc and PFC subregions were also associated with lower concentrations of DA and greater HVA:DA ratios (p's<0.05). Overall, these data suggest that increased inflammatory signaling driving heightened CRP levels may mediate the adverse consequences of obesogenic diets on DA neurochemistry and corticostriatal connectivity.

PMID: 32240763 [PubMed - as supplied by publisher]

Weight loss reduces head motion: Revisiting a major confound in neuroimaging.

Fri, 04/03/2020 - 21:45
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Weight loss reduces head motion: Revisiting a major confound in neuroimaging.

Hum Brain Mapp. 2020 Apr 02;:

Authors: Beyer F, Prehn K, Wüsten KA, Villringer A, Ordemann J, Flöel A, Witte AV

Abstract
Head motion during magnetic resonance imaging (MRI) induces image artifacts that affect virtually every brain measure. In parallel, cross-sectional observations indicate a correlation of head motion with age, psychiatric disease status and obesity, raising the possibility of a systematic artifact-induced bias in neuroimaging outcomes in these conditions, due to the differences in head motion. Yet, a causal link between obesity and head motion has not been tested in an experimental design. Here, we show that a change in body mass index (BMI) (i.e., weight loss after bariatric surgery) systematically decreases head motion during MRI. In this setting, reduced imaging artifacts due to lower head motion might result in biased estimates of neural differences induced by changes in BMI. Overall, our finding urges the need to rigorously control for head motion during MRI to enable valid results of neuroimaging outcomes in populations that differ in head motion due to obesity or other conditions.

PMID: 32239733 [PubMed - as supplied by publisher]

Functional Connectivity of Hippocampal CA3 Predicts Neurocognitive Aging via CA1-Frontal Circuit.

Fri, 04/03/2020 - 21:45
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Functional Connectivity of Hippocampal CA3 Predicts Neurocognitive Aging via CA1-Frontal Circuit.

Cereb Cortex. 2020 Apr 02;:

Authors: Liang X, Hsu LM, Lu H, Ash JA, Rapp PR, Yang Y

Abstract
The CA3 and CA1 principal cell fields of the hippocampus are vulnerable to aging, and age-related dysfunction in CA3 may be an early seed event closely linked to individual differences in memory decline. However, whether the differential vulnerability of CA3 and CA1 is associated with broader disruption in network-level functional interactions in relation to age-related memory impairment, and more specifically, whether CA3 dysconnectivity contributes to the effects of aging via CA1 network connectivity, has been difficult to test. Here, using resting-state fMRI in a group of aged rats uncontaminated by neurodegenerative disease, aged rats displayed widespread reductions in functional connectivity of CA3 and CA1 fields. Age-related memory deficits were predicted by connectivity between left CA3 and hippocampal circuitry along with connectivity between left CA1 and infralimbic prefrontal cortex. Notably, the effects of CA3 connectivity on memory performance were mediated by CA1 connectivity with prefrontal cortex. We additionally found that spatial learning and memory were associated with functional connectivity changes lateralized to the left CA3 and CA1 divisions. These results provide novel evidence that network-level dysfunction involving interactions of CA3 with CA1 is an early marker of poor cognitive outcome in aging.

PMID: 32239141 [PubMed - as supplied by publisher]

Increased intrinsic default-mode network activity as a compensatory mechanism in aMCI: a resting-state functional connectivity MRI study.

Fri, 04/03/2020 - 21:45
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Increased intrinsic default-mode network activity as a compensatory mechanism in aMCI: a resting-state functional connectivity MRI study.

Aging (Albany NY). 2020 Apr 01;12:

Authors: Liang J, Li Y, Liu H, Zhang S, Wang M, Chu Y, Ye J, Xi Q, Zhao X

Abstract
Numerous studies have investigated the differences in the mean functional connectivity (FC) strength between amnestic mild cognitive impairment (aMCI) patients and normal subjects using resting-state functional magnetic resonance imaging. However, whether the mean FC is increased, decreased or unchanged in aMCI patients compared to normal controls remains unclear. Two factors might lead to inconsistent results: the determination of regions of interest and the reliability of the FC.We explored differences in FC and the degree centrality (Dc) constructed by the bootstrap method, between and within networks (default-mode network (DN), frontoparietal control network (CN), dorsal attention network (AN)), and resulting from a hierarchical-clustering algorithm.The mean FC within the DN and CN was significantly increased (P < 0.05, uncorrected) in patients. Significant increases (P < 0.05, uncorrected) in the mean FC were found in patients between DN and CN and between DN and AN. Five pairs of FC (false discovery rate corrected) and the Dc of six regions (Bonferroni corrected) displayed a significant increase in patients. Lower cognitive ability was significantly associated with a greater increase in the Dc of the left superior temporal sulcus.Our results demonstrate that the early dysfunctions in aMCI disease are mainly compensatory impairments.

PMID: 32238610 [PubMed - as supplied by publisher]

Gut microbiota from persons with attention-deficit/hyperactivity disorder affects the brain in mice.

Fri, 04/03/2020 - 21:45
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Gut microbiota from persons with attention-deficit/hyperactivity disorder affects the brain in mice.

Microbiome. 2020 Apr 01;8(1):44

Authors: Tengeler AC, Dam SA, Wiesmann M, Naaijen J, van Bodegom M, Belzer C, Dederen PJ, Verweij V, Franke B, Kozicz T, Arias Vasquez A, Kiliaan AJ

Abstract
BACKGROUND: The impact of the gut microbiota on host physiology and behavior has been relatively well established. Whether changes in microbial composition affect brain structure and function is largely elusive, however. This is important as altered brain structure and function have been implicated in various neurodevelopmental disorders, like attention-deficit/hyperactivity disorder (ADHD). We hypothesized that gut microbiota of persons with and without ADHD, when transplanted into mice, would differentially modify brain function and/or structure. We investigated this by colonizing young, male, germ-free C57BL/6JOlaHsd mice with microbiota from individuals with and without ADHD. We generated and analyzed microbiome data, assessed brain structure and function by magnetic resonance imaging (MRI), and studied mouse behavior in a behavioral test battery.
RESULTS: Principal coordinate analysis showed a clear separation of fecal microbiota of mice colonized with ADHD and control microbiota. With diffusion tensor imaging, we observed a decreased structural integrity of both white and gray matter regions (i.e., internal capsule, hippocampus) in mice that were colonized with ADHD microbiota. We also found significant correlations between white matter integrity and the differentially expressed microbiota. Mice colonized with ADHD microbiota additionally showed decreased resting-state functional MRI-based connectivity between right motor and right visual cortices. These regions, as well as the hippocampus and internal capsule, have previously been reported to be altered in several neurodevelopmental disorders. Furthermore, we also show that mice colonized with ADHD microbiota were more anxious in the open-field test.
CONCLUSIONS: Taken together, we demonstrate that altered microbial composition could be a driver of altered brain structure and function and concomitant changes in the animals' behavior. These findings may help to understand the mechanisms through which the gut microbiota contributes to the pathobiology of neurodevelopmental disorders. Video abstract.

PMID: 32238191 [PubMed - as supplied by publisher]

A review on epileptic foci localization using resting-state functional magnetic resonance imaging.

Fri, 04/03/2020 - 21:45
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A review on epileptic foci localization using resting-state functional magnetic resonance imaging.

Math Biosci Eng. 2020 Feb 26;17(3):2496-2515

Authors: Shi Y, Zhang X, Yang CL, Ren JC, Li ZM, Wang Q

Abstract
Epilepsy is a brain syndrome caused by synchronous abnormal discharge of brain neurons. As an effective treatment for epilepsy, successful surgical resection requires accurate localization of epileptic foci to avoid iatrogenic disability. Previous studies have demonstrated the potential of restingstate functional magnetic resonance imaging (rs-fMRI) technique to localize epileptic foci though clinical applications of rs-fMRI are still at an early stage of development. fMRI data analysis approaches seek pre-defined regressors modeling contributions to the voxel time series, including the BOLD response following neuronal activation. In present study, localization strategies of epileptic foci in rs-fMRI technology were classified and summarized. To begin with, data-driven approaches attempting to determine the intrinsic structure of the data were discussed in detail. Then, as novel fMRI data analysis methods, deconvolution algorithms such as total activation (TA) and blind deconvolution were discussed, which were applied to explore the underlying activity-inducing signal of the BOLD signal. Lastly, effective connectivity approaches such as autocorrelation function method and Pearson correlation coefficient have also been proposed to identify the brain regions driving the generation of seizures within the epileptic network. In the future, fMRI technology can be used as a supplement of intraoperative subdural electrode method or combined with traditional epileptic focus localization technologies, which is one of the most attractive aspect in clinic. It may also play an important role in providing diagnostic information for epilepsy patients.

PMID: 32233551 [PubMed - in process]

Multimodal analysis using [11C]PiB-PET/MRI for functional evaluation of patients with Alzheimer's disease.

Thu, 04/02/2020 - 21:43
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Multimodal analysis using [11C]PiB-PET/MRI for functional evaluation of patients with Alzheimer's disease.

EJNMMI Res. 2020 Mar 30;10(1):30

Authors: Okazawa H, Ikawa M, Jung M, Maruyama R, Tsujikawa T, Mori T, Rahman MGM, Makino A, Kiyono Y, Kosaka H

Abstract
BACKGROUND: Multimodal PET/MRI image data simultaneously obtained from patients with early-stage of Alzheimer's disease (eAD) were assessed in order to observe pathophysiologic and functional changes, as well as alterations of morphology and connectivity in the brain. Fifty-eight patients with mild cognitive impairment and early dementia (29 males, 69 ± 12 years) underwent [11C]Pittsburgh compound-B (PiB) PET/MRI with 70-min PET and MRI scans. Sixteen age-matched healthy controls (CTL) (9 males, 68 ± 11 years) were also studied with the same scanning protocol. Cerebral blood flow (CBF) was calculated from the early phase PET images using the image-derived input function method. A standardized uptake value ratio (SUVr) was calculated from 50 to 70 min PET data with a reference region of the cerebellar cortex. MR images such as 3D-T1WI, resting-state functional MRI (RS-fMRI), diffusion tensor image (DTI), and perfusion MRI acquired during the dynamic PET scan were also analyzed to evaluate various brain functions on MRI.
RESULTS: Twenty-seven of the 58 patients were determined as eAD based on the results of PiB-PET and clinical findings, and a total of 43 subjects' data including CTL were analyzed in this study. PiB SUVr values in all cortical regions of eAD were significantly greater than those of CTL. The PiB accumulation intensity was negatively correlated with cognitive scores. The regional PET-CBF values of eAD were significantly lower in the bilateral parietal lobes and right temporal lobe compared with CTL, but not in MRI perfusion; however, SPM showed regional differences on both PET- and MRI-CBF. SPM analysis of RS-fMRI delineated regional differences between the groups in the anterior cingulate cortex and the left precuneus. VBM analysis showed atrophic changes in the AD group in a part of the bilateral hippocampus; however, analysis of fractional anisotropy calculated from DTI data did not show differences between the two groups.
CONCLUSION: Multimodal analysis conducted with various image data from PiB-PET/MRI scans showed differences in regional CBF, cortical volume, and neuronal networks in different regions, indicating that pathophysiologic and functional changes in the AD brain can be observed from various aspects of neurophysiologic parameters. Application of multimodal brain images using PET/MRI would be ideal for investigating pathophysiologic changes in patients with dementia and other neurodegenerative diseases.

PMID: 32232573 [PubMed]

The Instant Spontaneous Neuronal Activity Modulation of Transcutaneous Auricular Vagus Nerve Stimulation on Patients With Primary Insomnia.

Thu, 04/02/2020 - 21:43
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The Instant Spontaneous Neuronal Activity Modulation of Transcutaneous Auricular Vagus Nerve Stimulation on Patients With Primary Insomnia.

Front Neurosci. 2020;14:205

Authors: Zhao B, Bi Y, Li L, Zhang J, Hong Y, Zhang L, He J, Fang J, Rong P

Abstract
Primary insomnia (PI) is associated with increased spontaneous neuronal activity. Transcutaneous auricular vagus nerve stimulation (taVNS) modulates brain function, and it is an effective treatment for primary insomnia. However, whether taVNS alleviates insomnia through modulating spontaneous neuronal activity is not fully clarified. This study aims to investigate the instant effect of taVNS in modulating spontaneous neuronal activity in PI patients using resting-state functional magnetic resonance imaging (rs-fMRI). Twenty-two PI subjects underwent rs-fMRI scanning prior and immediately after 30 min treatment of taVNS controlled by twenty healthy adults. Amplitude of low frequency fluctuations (ALFF) analysis was employed to assess the difference in spontaneous neuronal activity between PI patients and healthy adults, as well as between pre-treatment and post-treatment of taVNS. The taVNS-induced altered ALFF brain areas were then selected as regions of interest to perform the resting state functional connectivity (RSFC) analysis in PI patients. The right precuneus showed significantly increased ALFF in PI patients. After immediate taVNS treatment, the ALFF was significantly decreased in the right precuneus and increased in the left middle occipital gyrus. The RSFC in right precuneus with right angular, right superior frontal gyrus, and right middle frontal gyrus was significantly decreased. This study provides insights into the instant brain effects of taVNS on PI patients.

PMID: 32231517 [PubMed]

A study on BOLD fMRI of the brain basic activities of MDD and the first-degree relatives.

Thu, 04/02/2020 - 21:43
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A study on BOLD fMRI of the brain basic activities of MDD and the first-degree relatives.

Int J Psychiatry Clin Pract. 2020 Mar 31;:1-9

Authors: Song Y, Shen X, Mu X, Mao N, Wang B

Abstract
Introduction: The present study aims to explore the characteristics and differences of the ReHo, ALFF and fALFF of brain in the resting state of depression and first-degree relatives, in order to identify candidate central prodromal biomarkers of depression.Method: Three groups of medication-free patients (39-59 years old) was involved in this study, including the patients with major depression disorder (MDD group, n = 15), healthy volunteers with first-degree relatives with MDD (first-degree relatives group, n = 15), healthy volunteers with no personal or family history of MDD (the control group [HC], n = 15). Participants underwent functional MRI while staying in a resting state after a conventional MRI scanning on a clinical 3 T system(Siemens Skyra, Germany).Results: The ReHo, ALFF and fALFF values are different in brain of MDD, first-degree relatives, and HC (p<.05). MDD patients exhibited abnormal spontaneous activity in multiple brain regions which are closely related to emotion regulation and perception. The present findings provide further insight into the pathological mechanisms underlying MDD.Conclusion: With the widespread abnormal values of brain in MDD and first-degree relatives measured, we can get a hypothesis that these abnormalities may be associated with cognitive network disorders and emotional distress in MDD.Key pointsThe fMRI could increase the early validity of MDD as a new diagnostic and disease-monitoring tool.Monitoring ReHo, ALFF, fALFF values using fMRI can provide insight into the presence and evolution of MDD disease and permit objective evaluation of brain abnormalities.It appears that ReHo, ALFF, fALFF could be used as markers for monitoring disease progression and treatment effects in MDD patients in the future.

PMID: 32228280 [PubMed - as supplied by publisher]

Magnetic resonance imaging biomarkers of brain connectivity in predicting outcome after mild traumatic brain injury: a systematic review.

Thu, 04/02/2020 - 21:43
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Magnetic resonance imaging biomarkers of brain connectivity in predicting outcome after mild traumatic brain injury: a systematic review.

J Neurotrauma. 2020 Mar 31;:

Authors: Puig J, Ellis M, Kornelsen J, Figley TD, Figley CR, Daunis-I-Estadella P, Mutch A, Essig M

Abstract
There is growing interest in developing magnetic resonance imaging (MRI) biomarkers of brain connectivity from resting-state functional (rs-fMRI) and diffusion tensor imaging (DTI) to aid in the management of patients with mild traumatic brain injury (mTBI). To determine whether early MRI biomarkers of brain connectivity are useful in predicting outcome after mTBI, we conducted a systematic review using the following inclusion criteria: (1) patients aged>16 years with mTBI, (2) MRI performed during the first month post-injury, (3) outcome measure available, (4) control group, and (5) original paper published in a peer-reviewed journal. Of the 1351 citations identified, 14 studies met inclusion criteria (5 rs-fMRI and 10 DTI; 680 mTBI patients vs 436 controls) including those where MRI was performed from <12 hours to 1 month post-injury. The most common clinical outcome measure used in these studies was symptom burden using the Rivermead Post-Concussion Questionnaire. The most frequently studied brain connectivity MRI biomarkers were global functional connectivity, default-mode network, and fractional anisotropy. Despite the scant evidence and considerable methodological heterogeneity observed among studies, we conclude that brain connectivity MRI biomarkers obtained within one month of injury may be potentially useful in predicting outcome in mTBI. Further longitudinal studies are needed to evaluate the effect of mTBI on MRI-based brain connectivity biomarkers and examine how incorporation of these tests can inform the clinical care of individual mTBI patients.

PMID: 32228145 [PubMed - as supplied by publisher]

Global fMRI signal at rest relates to symptom severity in schizophrenia.

Tue, 03/31/2020 - 21:42
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Global fMRI signal at rest relates to symptom severity in schizophrenia.

Schizophr Res. 2020 Mar 25;:

Authors: Umeh A, Kumar J, Francis ST, Liddle PF, Palaniyappan L

PMID: 32222349 [PubMed - as supplied by publisher]

Neural Basis of Smoking-Related Difficulties in Emotion Regulation.

Mon, 03/30/2020 - 21:40
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Neural Basis of Smoking-Related Difficulties in Emotion Regulation.

Int J Neuropsychopharmacol. 2020 Mar 27;:

Authors: Faulkner P, Dean AC, Ghahremani DG, London ED

Abstract
BACKGROUND: Negative emotional states contribute to cigarette smoking, and difficulties in regulating these states can hinder smoking cessation. Understanding the neural bases of these difficulties in smokers may facilitate development of novel therapies for Tobacco Use Disorder.
METHODS: Thirty-seven participants (18 smokers, 19 nonsmokers; 16-21 years old) completed the Difficulties in Emotion Regulation Scale (DERS), which is comprised of 6 subscales (lack of emotional clarity, lack of emotional awareness, limited access to emotion regulation strategies, nonacceptance of emotional responses, difficulties engaging in goal-directed behaviors, and impulse control difficulties) that combine to provide a total score. Participants also underwent functional magnetic resonance imaging to determine resting-state functional connectivity of the amygdala. Separate ANOVAs were used to determine group differences in self-reports on the DERS. Voxel-wise linear mixed models were performed to determine whether group influenced relationships between whole-brain functional connectivity of the amygdala and scores on the DERS.
RESULTS: Compared with nonsmokers, smokers reported greater difficulties in emotion regulation, denoted by higher total scores on the DERS. Group differences were observed on a subscale of lack of emotional clarity, but no other subscale differences on the DERS were observed. Nonsmokers exhibited a greater negative correlation than smokers between lack of emotional clarity scores and connectivity of the amygdala with the left inferior frontal gyrus. Finally, this amygdala-to-left inferior frontal gyrus connectivity was weaker in smokers than in nonsmokers.
CONCLUSIONS: These findings suggest that difficulties in emotion regulation in smokers are at least partially due to lack of emotional clarity. Given the role of the inferior frontal gyrus in understanding emotional states, strengthening connectivity between the amygdala and the inferior frontal gyrus may improve emotional clarity to help smokers regulate their negative emotions, thereby improving their ability to quit smoking.

PMID: 32221527 [PubMed - as supplied by publisher]

Electrical status epilepticus in sleep affects intrinsically connected networks in patients with benign childhood epilepsy with centrotemporal spikes.

Mon, 03/30/2020 - 21:40
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Electrical status epilepticus in sleep affects intrinsically connected networks in patients with benign childhood epilepsy with centrotemporal spikes.

Epilepsy Behav. 2020 Mar 25;106:107032

Authors: He W, Liu H, Liu Z, Wu Q

Abstract
BACKGROUND: Although outcomes of benign childhood epilepsy with centrotemporal spikes (BECTS) are frequently excellent, some atypical forms of BECTS, especially electrical status epilepticus in sleep (ESES), are characterized by worse outcomes and negative impacts on cognitive development.
METHODS: To explore specific ESES-related brain networks in patients with BECTS, we used resting-state functional magnetic resonance imaging (fMRI) to scan patients with BECTS with ESES (n = 9), patients with BECTS without ESES (n = 17), and healthy controls (n = 36). Unbiased seed-based whole-brain functional connectivity (FC) was adopted to explore the connectivity mode of three resting-state cerebral networks: the default mode network (DMN), salience network (SN), and central executive network (CEN).
RESULTS: Compared with the other two groups, patients with BECTS with ESES showed FC in the SN or in the CEN decreased, but not in the DMN. Moreover, we found the FC in the CEN in patients with BECTS without ESES decreased when compared with controls. Our currently intrinsically defined anticorrelated networks strength was disrupted in BECTS and connote greater deactivation than the results from FC for a seed region in children with BECTS.
CONCLUSION: These results indicated that children with BECTS with ESES showed brain activity altered in the CEN and the SN. The difference of impairment in the SN and CEN may lead to improve the understanding of the underlying neuropathophysiology, and to assess the activity of patients with BECTS with ESES, which is crucial for measuring disease activity, improving patient care, and assessing the effect of antiepilepsy therapy.

PMID: 32220803 [PubMed - as supplied by publisher]

Impaired connectivity within neuromodulatory networks in multiple sclerosis and clinical implications.

Sun, 03/29/2020 - 21:39
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Impaired connectivity within neuromodulatory networks in multiple sclerosis and clinical implications.

J Neurol. 2020 Mar 26;:

Authors: Carotenuto A, Wilson H, Giordano B, Caminiti SP, Chappell Z, Williams SCR, Hammers A, Silber E, Brex P, Politis M

Abstract
There is mounting evidence regarding the role of impairment in neuromodulatory networks for neurodegenerative diseases, such as Parkinson's and Alzheimer's disease. However, the role of neuromodulatory networks in multiple sclerosis (MS) has not been assessed. We applied resting-state functional connectivity and graph theory to investigate the changes in the functional connectivity within neuromodulatory networks including the serotonergic, noradrenergic, cholinergic, and dopaminergic systems in MS. Twenty-nine MS patients and twenty-four age- and gender-matched healthy controls performed clinical and cognitive assessments including the expanded disability status score, symbol digit modalities test, and Hamilton Depression rating scale. We demonstrated a diffuse reorganization of network topography (P < 0.01) in serotonergic, cholinergic, noradrenergic, and dopaminergic networks in patients with MS. Serotonergic, noradrenergic, and cholinergic network functional connectivity derangement was associated with disease duration, EDSS, and depressive symptoms (P < 0.01). Derangements in serotonergic, noradrenergic, cholinergic, and dopaminergic network impairment were associated with cognitive abilities (P < 0.01). Our results indicate that functional connectivity changes within neuromodulatory networks might be a useful tool in predicting disability burden over time, and could serve as a surrogate endpoint to assess efficacy for symptomatic treatments.

PMID: 32219555 [PubMed - as supplied by publisher]

Heterogeneity of executive function revealed by a functional random forest approach across ADHD and ASD.

Sun, 03/29/2020 - 21:39
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Heterogeneity of executive function revealed by a functional random forest approach across ADHD and ASD.

Neuroimage Clin. 2020 Mar 16;26:102245

Authors: Cordova M, Shada K, Demeter DV, Doyle O, Miranda-Dominguez O, Perrone A, Schifsky E, Graham A, Fombonne E, Langhorst B, Nigg J, Fair DA, Feczko E

Abstract
BACKGROUND: Those with autism spectrum disorder (ASD) and/or attention-deficit-hyperactivity disorder (ADHD) exhibit symptoms of hyperactivity and inattention, causing significant hardships for families and society. A potential mechanism involved in these conditions is atypical executive function (EF). Inconsistent findings highlight that EF features may be shared or distinct across ADHD and ASD. With ADHD and ASD each also being heterogeneous, we hypothesized that there may be nested subgroups across disorders with shared or unique underlying mechanisms.
METHODS: Participants (N = 130) included adolescents aged 7-16 with ASD (n = 64) and ADHD (n = 66). Typically developing (TD) participants (n = 28) were included for a comparative secondary sub-group analysis. Parents completed the K-SADS and youth completed an extended battery of executive and other cognitive measures. A two stage hybrid machine learning tool called functional random forest (FRF) was applied as a classification approach and then subsequently to subgroup identification. We input 43 EF variables to the classification step, a supervised random forest procedure in which the features estimated either hyperactive or inattentive ADHD symptoms per model. The FRF then produced proximity matrices and identified optimal subgroups via the infomap algorithm (a type of community detection derived from graph theory). Resting state functional connectivity MRI (rs-fMRI) was used to evaluate the neurobiological validity of the resulting subgroups.
RESULTS: Both hyperactive (Mean absolute error (MAE) = 0.72, Null model MAE = 0.8826, (t(58) = -4.9, p < .001) and inattentive (MAE = 0.7, Null model MAE = 0.85, t(58) = -4.4, p < .001) symptoms were predicted better than chance by the EF features selected. Subgroup identification was robust (Hyperactive: Q = 0.2356, p < .001; Inattentive: Q = 0.2350, p < .001). Two subgroups representing severe and mild symptomology were identified for each symptom domain. Neuroimaging data revealed that the subgroups and TD participants significantly differed within and between multiple functional brain networks, but no consistent "severity" patterns of over or under connectivity were observed between subgroups and TD.
CONCLUSION: The FRF estimated hyperactive/inattentive symptoms and identified 2 distinct subgroups per model, revealing distinct neurocognitive profiles of Severe and Mild EF performance per model. Differences in functional connectivity between subgroups did not appear to follow a severity pattern based on symptom expression, suggesting a more complex mechanistic interaction that cannot be attributed to symptom presentation alone.

PMID: 32217469 [PubMed - as supplied by publisher]

Salience-thalamic circuit uncouples in major depressive disorder, but not in bipolar depression.

Sun, 03/29/2020 - 21:39
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Salience-thalamic circuit uncouples in major depressive disorder, but not in bipolar depression.

J Affect Disord. 2020 Mar 03;269:43-50

Authors: Zeng C, Xue Z, Ross B, Zhang M, Liu Z, Wu G, Ouyang X, Li D, Pu W

Abstract
BACKGROUND: Bipolar depression (BDD) and major depressive disorder (MDD) are two diseases both characterized by depressed mood and diminished interest or pleasure. Recent neuroimaging studies have implicated the thalamo-cortical circuit in mood disorders, and the present study aimed to map thalamo-cortical connectivity to explore the dissociable and common abnormalities between bipolar and major depression in this circuit.
METHOD: Applying resting-state functional magnetic resonance imaging (fMRI), we mapped the thalamo-cortical circuit using a fine-grained thalamic atlas with 8 sub-regions bilaterally in 38 BDD patients, 42 MDD patients and 39 healthy controls (HCs). Correlation analysis was then performed between thalamo-cortical connectivity and clinical variables.
RESULT: The findings showed that both patient groups exhibited prefronto-thalamo-cerebellar and sensorimotor-thalamic hypoconnectivity, while the abnormalities in MDD were more extensive. Particularly, MDD group showed decreased thalamic connectivity with the salience network including the insula, anterior cingulate cortex (ACC), and striatum. No correlations were found between the abnormal thalamo-cortical connectivity and clinical symptoms in either patient group.
LIMITATION: Most patients in our study were taking drugs at the time of scanning, which may confound our findings.
CONCLUSION: Our finding suggest that the thalamo-cortical hypofunction is a common neuro-substrate for BDD and MDD. Specifically, the hypoconnectivity between the thalamus and salience network including the insula, ACC and striatum may be a distinguished biomarker for MDD, which may help to differentiate these two emotional disorders.

PMID: 32217342 [PubMed - as supplied by publisher]

Disturbed resting-state whole-brain functional connectivity of striatal subregions in bulimia nervosa.

Sat, 03/28/2020 - 21:37
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Disturbed resting-state whole-brain functional connectivity of striatal subregions in bulimia nervosa.

Int J Neuropsychopharmacol. 2020 Mar 26;:

Authors: Wang L, Bi K, Song Z, Zhang Z, Li K, Kong QM, Li XN, Lu Q, Si TM

Abstract
BACKGROUND: Disturbed self-regulation, taste reward, as well as somatosensory and visuospatial processes were thought to drive binge eating and purging behaviors that characterize bulimia nervosa (BN). Although studies have implicated a central role of the striatum in these dysfunctions, there have been no direct investigations on striatal functional connectivity (FC) in BN from a network perspective.
METHOD: We calculated the FC of striatal subregions based on the resting-state fMRI data of 51 BN patients and 53 healthy women.
RESULTS: Compared with the healthy women, BN patients showed increased positive FC in bilateral striatal nuclei and thalamus for nearly all of the striatal subregions, and increased negative FC in bilateral primary sensorimotor cortex and occipital areas for both ventral striatum and putamen subregions. Only for the putamen subregions, we observed reduced negative FC in the prefrontal (bilateral superior and middle frontal gyri) and parietal (right inferior parietal lobe and precuneus) areas. Several striatal connectivities with occipital and primary sensorimotor cortex significantly correlated with the severity of bulimia.
CONCLUSION: The findings indicate BN-related alterations in striatal FC with the dorsolateral prefrontal cortex supporting self-regulation, the subcortical striatum and thalamus involved in taste reward, as well as the visual occipital and sensorymotor regions mediating body image, which contribute to our understanding of neural circuitry of BN and encourage future therapeutic developments for BN by modulating striatal pathway.

PMID: 32215560 [PubMed - as supplied by publisher]

Differential Effects of Tai Chi Chuan (Motor-Cognitive Training) and Walking on Brain Networks: A Resting-State fMRI Study in Chinese Women Aged 60.

Sat, 03/28/2020 - 21:37
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Differential Effects of Tai Chi Chuan (Motor-Cognitive Training) and Walking on Brain Networks: A Resting-State fMRI Study in Chinese Women Aged 60.

Healthcare (Basel). 2020 Mar 24;8(1):

Authors: Yue C, Zhang Y, Jian M, Herold F, Yu Q, Mueller P, Lin J, Wang G, Tao Y, Zhang Z, Zou L

Abstract
Background: This cross-sectional study aimed to investigate whether a long-term engagement in different types of physical exercise may influence resting-state brain networks differentially. In particular, we studied if there were differences in resting-state functional connectivity measures when comparing older women who are long-term practitioners of tai chi chuan or walking. Method: We recruited 20 older women who regularly practiced tai chi chuan (TCC group), and 22 older women who walked regularly (walking group). Both the TCC group and the walking group underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scan. The acquired rs-fMRI data of all participants were analyzed using independent component analysis. Age and years of education were added as co-variables. Results: There were significant differences in default network, sensory-motor network, and visual network of rs-fMRI between the TCC group and walking group (p < 0.05). Conclusions: The findings of the current study suggested that long-term practice of different types of physical exercises (TCC vs. walking) influenced brain functional networks and brain functional plasticity of elderly women differentially. Our findings encourage further research to investigate whether those differences in resting-state functional connectivity as a function of the type of physical exercise have implications for the prevention of neurological diseases.

PMID: 32213980 [PubMed]

Resting state networks activity in euthymic Bipolar Disorder.

Sat, 03/28/2020 - 03:37
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Resting state networks activity in euthymic Bipolar Disorder.

Bipolar Disord. 2020 Mar 25;:

Authors: Bellani M, Bontempi P, Zovetti N, Rossetti MG, Perlini C, Dusi N, Squarcina L, Marinelli V, Zoccatelli G, Alessandrini F, Ciceri EFM, Sbarbati A, Brambilla P

Abstract
OBJECTIVES: Bipolar disorder (BD) is a psychiatric condition causing shifts in mood, energy and activity levels severely altering the quality of life of the patients even in the euthymic phase. Although widely accepted, the neurobiological bases of the disorder in the euthymic phase remain elusive. This study aims at characterizing resting state functional activity of the BD euthymic phase in order to better understand the pathogenesis of the disease and build future neurobiological models.
METHODS: Fifteen euthymic BD patients (10 females; mean age 40.2; standard deviation 13.5; range 20-61) and 27 healthy controls (HC) (21 females; mean age 37; standard deviation 10.6; range 22-60) underwent a 3T functional MRI scan at rest. Resting state activity was extracted through independent component analysis (ICA) run with automatic dimensionality estimation.
RESULTS: ICA identified 22 resting state networks (RSNs). Within-network analysis revealed decreased connectivity in the visual, temporal, motor and cerebellar RSNs of BD patients versus HC. Between-network analysis showed increased connectivity between motor area and the default mode network (DMN) partially overlapping with the fronto-parietal network (FPN) in BD patients.
CONCLUSION: Within-network analysis confirmed existing evidence of altered cerebellar, temporal, motor and visual networks in BD. Increased connectivity between the DMN and the motor area network suggests the presence of alterations of the fronto-parietal regions, precuneus and cingulate cortex in the euthymic condition. These findings indicate that specific connectivity alterations might persist even in the euthymic state suggesting the importance of examining both within and between-network connectivity to achieve a global understanding of the BD euthymic condition.

PMID: 32212391 [PubMed - as supplied by publisher]

The Reorganization of Insular Subregions in Individuals with Below-Level Neuropathic Pain following Incomplete Spinal Cord Injury.

Sat, 03/28/2020 - 03:37
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The Reorganization of Insular Subregions in Individuals with Below-Level Neuropathic Pain following Incomplete Spinal Cord Injury.

Neural Plast. 2020;2020:2796571

Authors: Li X, Wang L, Chen Q, Hu Y, Du J, Chen X, Zheng W, Lu J, Chen N

Abstract
Objective: To investigate the reorganization of insular subregions in individuals suffering from neuropathic pain (NP) after incomplete spinal cord injury (ISCI) and further to disclose the underlying mechanism of NP.
Method: The 3D high-resolution T1-weighted structural images and resting-state functional magnetic resonance imaging (rs-fMRI) of all individuals were obtained using a 3.0 Tesla MRI system. A comparative analysis of structure and function connectivity (FC) with insular subareas as seeds in 10 ISCI individuals with below-level NP (ISCI-P), 11 ISCI individuals without NP (ISCI-N), and 25 healthy controls (HCs) was conducted. Associations between the structural and functional alteration of insula subregions and visual analog scale (VAS) scores were analyzed using the Pearson correlation in SPSS 20.
Results: Compared with ISCI-N patients, when the left posterior insula as the seed, ISCI-P showed increased FC in right cerebellum VIIb and cerebellum VIII, Brodmann 37 (BA 37). When the left ventral anterior insula as the seed, ISCI-P indicated enhanced FC in right BA18 compared with ISCI-N patients. These increased FCs positively correlated with VAS scores. Relative to HCs, ISCI-P presented increased FC in the left hippocampus when the left dorsal anterior insula was determined as the seed. There was no statistical difference in the volume of insula subregions among the three groups.
Conclusion: Our study indicated that distinctive patterns of FC in each subregion of insula suggest that the insular subareas participate in the NP processing through different FC following ISCI. Further, insula subregions could serve as a therapeutic target for NP following ISCI.

PMID: 32211038 [PubMed - in process]