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Tracing the structural origins of atypical language representation: consequences of prenatal mirror-imaged brain asymmetries in a dizygotic twin couple.

Wed, 08/01/2018 - 11:40
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Tracing the structural origins of atypical language representation: consequences of prenatal mirror-imaged brain asymmetries in a dizygotic twin couple.

Brain Struct Funct. 2018 Jul 30;:

Authors: Schuler AL, Bartha-Doering L, Jakab A, Schwartz E, Seidl R, Kienast P, Lackner S, Langs G, Prayer D, Kasprian G

Abstract
We investigated the predictive value of prenatal superior temporal sulcus (STS) depth asymmetry in a special case of a female dizygotic twin that showed inverted prenatal asymmetry of this structure. For this purpose, we performed a follow-up investigation in this former fetus at the age of seven, where we assessed the functional language lateralization using task-based and resting-state functional magnetic resonance imaging (fMRI). As control group we employed her twin brother, who showed a typical folding pattern prenatally, as well as a complementary set of four age-matched children that had fetal MRI of their brains and typical STS depth asymmetry. We could show that the twin with the atypical fetal asymmetry of the STS also showed significantly differing rightward language lateralization in the frontal and temporal lobes. Additionally, resting-state data suggest a stronger connectivity between inferior frontal gyri in this case. The twin showed normal cognitive development. This result gives a first glimpse into the STS' atypical asymmetry being a very early morphological marker for later language lateralization.

PMID: 30062562 [PubMed - as supplied by publisher]

Exploring Age-Related Changes in Resting State Functional Connectivity of the Amygdala: From Young to Middle Adulthood.

Wed, 08/01/2018 - 11:40
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Exploring Age-Related Changes in Resting State Functional Connectivity of the Amygdala: From Young to Middle Adulthood.

Front Aging Neurosci. 2018;10:209

Authors: Xiao T, Zhang S, Lee LE, Chao HH, van Dyck C, Li CR

Abstract
Functional connectivities of the amygdala support emotional and cognitive processing. Life-span development of resting-state functional connectivities (rsFC) of the amygdala may underlie age-related differences in emotion regulatory mechanisms. To date, age-related changes in amygdala rsFC have been reported through adolescence but not as thoroughly for adulthood. This study investigated age-related differences in amygdala rsFC in 132 young and middle-aged adults (19-55 years). Data processing followed published routines. Overall, amygdala showed positive rsFC with the temporal, sensorimotor and ventromedial prefrontal cortex (vmPFC), insula and lentiform nucleus, and negative rsFC with visual, frontoparietal, and posterior cingulate cortex and caudate head. Amygdala rsFC with the cerebellum was positively correlated with age, and rsFCs with the dorsal medial prefrontal cortex (dmPFC) and somatomotor cortex were negatively correlated with age, at voxel p < 0.001 in combination with cluster p < 0.05 FWE. These age-dependent changes in connectivity appeared to manifest to a greater extent in men than in women, although the sex difference was only evident for the cerebellum in a slope test of age regressions (p = 0.0053). Previous studies showed amygdala interaction with the anterior cingulate cortex (ACC) and vmPFC during emotion regulation. In region of interest analysis, amygdala rsFC with the ACC and vmPFC did not show age-related changes. These findings suggest that intrinsic connectivity of the amygdala evolved from young to middle adulthood in selective brain regions, and may inform future studies of age-related emotion regulation and maladaptive development of the amygdala circuits as an etiological marker of emotional disorders.

PMID: 30061823 [PubMed]

Gender differences in functional connectivities between insular subdivisions and selective pain-related brain structures.

Wed, 08/01/2018 - 11:40
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Gender differences in functional connectivities between insular subdivisions and selective pain-related brain structures.

J Headache Pain. 2018 Mar 14;19(1):24

Authors: Dai YJ, Zhang X, Yang Y, Nan HY, Yu Y, Sun Q, Yan LF, Hu B, Zhang J, Qiu ZY, Gao Y, Cui GB, Chen BL, Wang W

Abstract
BACKGROUND: The incidence of pain disorders in women is higher than in men, making gender differences in pain a research focus. The human insular cortex is an important brain hub structure for pain processing and is divided into several subdivisions, serving different functions in pain perception. Here we aimed to examine the gender differences of the functional connectivities (FCs) between the twelve insular subdivisions and selected pain-related brain structures in healthy adults.
METHODS: Twenty-six healthy males and 11 age-matched healthy females were recruited in this cross-sectional study. FCs between the 12 insular subdivisions (as 12 regions of interest (ROIs)) and the whole brain (ROI-whole brain level) or 64 selected pain-related brain regions (64 ROIs, ROI-ROI level) were measured between the males and females.
RESULTS: Significant gender differences in the FCs of the insular subdivisions were revealed: (1) The FCs between the dorsal dysgranular insula (dId) and other brain regions were significantly increased in males using two different techniques (ROI-whole brain and ROI-ROI analyses); (2) Based on the ROI-whole brain analysis, the FC increases in 4 FC-pairs were observed in males, including the left dId - the right median cingulate and paracingulate/ right posterior cingulate gyrus/ right precuneus, the left dId - the right median cingulate and paracingulate, the left dId - the left angular as well as the left dId - the left middle frontal gyrus; (3) According to the ROI-ROI analysis, increased FC between the left dId and the right rostral anterior cingulate cortex was investigated in males.
CONCLUSION: In summary, the gender differences in the FCs of the insular subdivisions with pain-related brain regions were revealed in the current study, offering neuroimaging evidence for gender differences in pain processing.
TRIAL REGISTRATION: ClinicalTrials.gov, NCT02820974 . Registered 28 June 2016.

PMID: 29541875 [PubMed - indexed for MEDLINE]

Fluid intelligence relates to the resting state amplitude of low-frequency fluctuation and functional connectivity: a multivariate pattern analysis.

Wed, 08/01/2018 - 11:40
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Fluid intelligence relates to the resting state amplitude of low-frequency fluctuation and functional connectivity: a multivariate pattern analysis.

Neuroreport. 2018 Jan 03;29(1):8-12

Authors: Li C, Yang G, Li M, Li B

Abstract
The goal of this study was to investigate the relationship between fluid intelligence (gF) and the pattern of the functional characteristics in the resting state in adults using multivariate pattern analysis. Resting-state functional images from 100 participants in the Human Connectome Project data set were analyzed. The amplitude of low-frequency fluctuation (ALFF) was first calculated, and a support vector regression approach was used to identify the association with gF. To discover whether the connectivity of the gF-associated areas was also related to gF, we further checked the seed-based functional connectivity using the seeds from the ALFF. The ALFF showed that gF was correlated with the left anterior cingulate cortex, which is involved in high cognitive control processes. The functional connectivity showed that the connection between the right prefrontal cortex (Brodmann area 8) and the left anterior cingulate cortex could predict gF. The multivariate pattern analysis result indicated that the brain functional activity and functional integrity that we identified have the potential to become an objective biomarker for evaluating individual differences in gF.

PMID: 29135806 [PubMed - indexed for MEDLINE]

Functional networks and network perturbations in rodents.

Wed, 08/01/2018 - 11:40
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Functional networks and network perturbations in rodents.

Neuroimage. 2017 Dec;163:419-436

Authors: Chuang KH, Nasrallah FA

Abstract
Synchronous low-frequency oscillation in the resting human brain has been found to form networks of functionally associated areas and hence has been widely used to map the functional connectivity of the brain using techniques such as resting-state functional MRI (rsfMRI). Interestingly, similar resting-state networks can also be detected in the anesthetized rodent brain, including the default mode-like network. This opens up opportunities for understanding the neurophysiological basis of the rsfMRI signal, the behavioral relevance of the network characteristics, connectomic deficits in diseases and treatment effects on brain connectivity using rodents, particularly transgenic mouse models. In this review, we will provide an overview on the resting-state networks in the rat and mouse brains, the effects of pharmacological agents, brain stimulation, structural connectivity, genetics on these networks, neuroplasticity after behavioral training and applications in models of neurological disease and psychiatric disorders. The influence of anesthesia, strain difference, and physiological variation on the rsfMRI-based connectivity measure will be discussed.

PMID: 28942060 [PubMed - indexed for MEDLINE]

Trajectories of brain system maturation from childhood to older adulthood: Implications for lifespan cognitive functioning.

Wed, 08/01/2018 - 11:40
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Trajectories of brain system maturation from childhood to older adulthood: Implications for lifespan cognitive functioning.

Neuroimage. 2017 Dec;163:125-149

Authors: Petrican R, Taylor MJ, Grady CL

Abstract
The human brain's intrinsic functional architecture reflects behavioural history and can help elucidate the neural mechanisms underlying age-related cognitive changes. To probe this issue, we used resting state (N = 586) and behavioural (N = 255) data from a lifespan sample and tested the interactions among ten intrinsic neural systems, derived from a well-established whole-brain parcellation. Our results revealed three distinguishable profiles, whose expression strengthened with increasing age and which characterized developmental differences in connectivity within the ten systems, between networks thought to underlie cognitive control and non-control systems, and among the non-control networks. The within-network connectivity profile was typified by decreased connectivity within two external processing networks (auditory/language and ventral attention). The non-control-to-non-control connectivity profile was typified by increased separation between networks involved in external processing, including language (dorsal attention, auditory) and those linked to internally generated cognitions and category learning (default mode, subcortical). Finally, the third connectivity profile was characterized by increased coupling of the three control networks (frontoparietal, salience, cingulo-opercular) with one another and with the remaining systems, particularly the subcortical and the two networks showing declining segregation with age. All three profiles showed significant associations with behavior during young adulthood, although these effects were less discernible during early development (before the age of 21) and degraded during late middle age and older adulthood. An exception to this trend was observed with respect to the within-network connectivity profile, whose "precocious" expression during early development predicted superior cognitive functioning. These findings thus help explain lifespan changes in the quality of mental processes, while also pointing to distinguishable mechanisms, which aid behavioural performance during different life stages.

PMID: 28917697 [PubMed - indexed for MEDLINE]

Neonatal brain injury and aberrant connectivity.

Tue, 07/31/2018 - 10:40

Neonatal brain injury and aberrant connectivity.

Neuroimage. 2018 Jul 27;:

Authors: Smyser CD, Wheelock MD, Limbrick DD, Neil JJ

Abstract
Brain injury sustained during the neonatal period may disrupt development of critical structural and functional connectivity networks leading to subsequent neurodevelopmental impairment in affected children. These networks can be characterized using structural (via diffusion MRI) and functional (via resting state-functional MRI) neuroimaging techniques. Advances in neuroimaging have led to expanded application of these approaches to study term- and prematurely-born infants, providing improved understanding of cerebral development and the deleterious effects of early brain injury. Across both modalities, neuroimaging data are conducive to analyses ranging from characterization of individual white matter tracts and/or resting state networks through advanced 'connectome-style' approaches identifying highly connected network hubs and investigating metrics of network topology such as modularity and small-worldness. We begin this review by summarizing the literature detailing structural and functional connectivity findings in healthy term and preterm infants without brain injury during the postnatal period, including discussion of early connectome development. We then detail common forms of brain injury in term- and prematurely-born infants. In this context, we next review the emerging body of literature detailing studies employing diffusion MRI, resting state-functional MRI and other complementary neuroimaging modalities to characterize structural and functional connectivity development in infants with brain injury. We conclude by reviewing technical challenges associated with neonatal neuroimaging, highlighting those most relevant to studying infants with brain injury and emphasizing the need for further targeted study in this high-risk population.

PMID: 30059733 [PubMed - as supplied by publisher]

Exploring the neuromechanism of chronic ephedrine addiction in rhesus monkeys: a behavioural and brain resting-state fMRI study.

Tue, 07/31/2018 - 10:40

Exploring the neuromechanism of chronic ephedrine addiction in rhesus monkeys: a behavioural and brain resting-state fMRI study.

Behav Brain Res. 2018 Jul 27;:

Authors: Xie L, Ma Y, Huang J, Guo R, Wang J, Sun Z, Duan S, Wu B, Lin Z, Xiao Y, Ma S

Abstract
Ephedrine is thought to exert behavioural effects primarily through actions on the central nervous system. However, the neuromechanism underlying the effects of ephedrine addiction still remains unclear. Our study aimed to establish chronic ephedrine addiction models in rhesus monkeys and to investigate the neuromechanism of chronic ephedrine addiction using the behavioural methods combined with resting-state blood oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI). Monkeys in the ephedrine addiction group (n = 6) received intramuscular injections of ephedrine using a dose escalation method, with a chronic model established in 8 weeks, while in the control group (n = 4), monkeys received a pure 0.9% saline injection. The weight and behaviors of the monkeys were observed throughout the treatment. All monkeys underwent the brain MR scans for two times (before treatment and after treatment had been discontinued). After molding, the weight of the ephedrine group was significantly reduced, while the weight of the control group increased significantly. Compared with the control group, the ephedrine addicted monkeys showed more abnormal behaviors related to addiction. In fMRI study, the ephedrine addicted monkeys showed more increased brain activation than that of the control group, mainly including the prefrontal cortex(PFC) and anterior cingulate cortex (ACC), the left ventral tegmental area(VTA), right insula, right amygdala, hippocampus, left thalamus, and left cerebellum.We hypothesize that the principal neuromechanism underlying chronic ephedrine addiction involves multiple abnormal brain neuron circuits, mainly in the PFC and the limbic system, and is closely related to addictive behaviors.

PMID: 30059694 [PubMed - as supplied by publisher]

Altered resting-state cerebellar-cerebral functional connectivity in obsessive-compulsive disorder.

Tue, 07/31/2018 - 10:40

Altered resting-state cerebellar-cerebral functional connectivity in obsessive-compulsive disorder.

Psychol Med. 2018 Jul 30;:1-10

Authors: Xu T, Zhao Q, Wang P, Fan Q, Chen J, Zhang H, Yang Z, Stein DJ, Wang Z

Abstract
BACKGROUND: The role of the cerebellum in obsessive-compulsive disorder (OCD) has drawn increasing attention. However, the functional connectivity between the cerebellum and the cerebral cortex has not been investigated in OCD, nor has the relationship between such functional connectivity and clinical symptoms.
METHODS: A total of 27 patients with OCD and 21 healthy controls (HCs) matched on age, sex and education underwent magnetic resonance imaging (MRI). Seed-based connectivity analyses were performed to examine differences in cerebellar-cerebral connectivity in patients with OCD compared with HCs. Associations between functional connectivity and clinical features in OCD were analyzed.
RESULTS: Compared with HCs, OCD patients showed significantly decreased cerebellar-cerebral functional connectivity in executive control and emotion processing networks. Within the OCD group, decreased functional connectivity in an executive network spanning the right cerebellar Crus I and the inferior parietal lobule was positively correlated with symptom severity, and decreased connectivity in an emotion processing network spanning the left cerebellar lobule VI and the lingual gyrus was negatively correlated with illness duration.
CONCLUSIONS: Altered functional connectivity between the cerebellum and cerebral networks involved in cognitive-affective processing in patients with OCD provides further evidence for the involvement of the cerebellum in the pathophysiology of OCD, and is consistent with impairment in executive control and emotion regulation in this condition.

PMID: 30058519 [PubMed - as supplied by publisher]

Consistency of magnetoencephalographic functional connectivity and network reconstruction using a template versus native MRI for co-registration.

Tue, 07/31/2018 - 10:40
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Consistency of magnetoencephalographic functional connectivity and network reconstruction using a template versus native MRI for co-registration.

Hum Brain Mapp. 2018 Jan;39(1):104-119

Authors: Douw L, Nieboer D, Stam CJ, Tewarie P, Hillebrand A

Abstract
INTRODUCTION: Studies using functional connectivity and network analyses based on magnetoencephalography (MEG) with source localization are rapidly emerging in neuroscientific literature. However, these analyses currently depend on the availability of costly and sometimes burdensome individual MR scans for co-registration. We evaluated the consistency of these measures when using a template MRI, instead of native MRI, for the analysis of functional connectivity and network topology.
METHODS: Seventeen healthy participants underwent resting-state eyes-closed MEG and anatomical MRI. These data were projected into source space using an atlas-based peak voxel and a centroid beamforming approach either using (1) participants' native MRIs or (2) the Montreal Neurological Institute's template. For both methods, time series were reconstructed from 78 cortical atlas regions. Relative power was determined in six classical frequency bands per region and globally averaged. Functional connectivity (phase lag index) between each pair of regions was calculated. The adjacency matrices were then used to reconstruct functional networks, of which regional and global metrics were determined. Intraclass correlation coefficients were calculated and Bland-Altman plots were made to quantify the consistency and potential bias of the use of template versus native MRI.
RESULTS: Co-registration with the template yielded largely consistent relative power, connectivity, and network estimates compared to native MRI.
DISCUSSION: These findings indicate that there is no (systematic) bias or inconsistency between template and native MRI co-registration of MEG. They open up possibilities for retrospective and prospective analyses to MEG datasets in the general population that have no native MRIs available. Hum Brain Mapp, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. Hum Brain Mapp 39:104-119, 2018. © 2017 Wiley Periodicals, Inc.

PMID: 28990264 [PubMed - indexed for MEDLINE]

Neurobiological Evidence for the Primacy of Mania Hypothesis.

Tue, 07/31/2018 - 10:40
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Neurobiological Evidence for the Primacy of Mania Hypothesis.

Curr Neuropharmacol. 2017 04;15(3):339-352

Authors: Kotzalidis GD, Rapinesi C, Savoja V, Cuomo I, Simonetti A, Ambrosi E, Panaccione I, Gubbini S, De Rossi P, De Chiara L, Janiri D, Sani G, Koukopoulos AE, Manfredi G, Napoletano F, Caloro M, Pancheri L, Puzella A, Callovini G, Angeletti G, Del Casale A

Abstract
BACKGROUND: Athanasios Koukopoulos proposed the primacy of mania hypothesis (PoM) in a 2006 book chapter and later, in two peer-reviewed papers with Nassir Ghaemi and other collaborators. This hypothesis supports that in bipolar disorder, mania leads to depression, while depression does not lead to mania.
OBJECTIVE: To identify evidence in literature that supports or falsifies this hypothesis.
METHOD: We searched the medical literature (PubMed, Embase, PsycINFO, and the Cochrane Library) for peer-reviewed papers on the primacy of mania, the default mode function of the brain in normal people and in bipolar disorder patients, and on illusion superiority until 6 June, 2016. Papers resulting from searches were considered for appropriateness to our objective. We adopted the PRISMA method for our review. The search for consistency with PoM was filtered through the neurobiological results of superiority illusion studies.
RESULTS: Out of a grand total of 139 records, 59 were included in our analysis. Of these, 36 were of uncertain value as to the primacy of mania hypothesis, 22 favoured it, and 1 was contrary, but the latter pooled patients in their manic and depressive phases, so to invalidate possible conclusions about its consistency with regard to PoM. All considered studies were not focused on PoM or superiority illusion, hence most of their results were, as expected, unrelated to the circuitry involved in superiority illusion. A considerable amount of evidence is consistent with the hypothesis, although indirectly so.
LIMITATIONS: Only few studies compared manic with depressive phases, with the majority including patients in euthymia.
CONCLUSION: It is possible that humans have a natural tendency for elation/optimism and positive self-consideration, that are more akin to mania; the depressive state could be a consequence of frustrated or unsustainable mania. This would be consistent with PoM.

PMID: 28503105 [PubMed - indexed for MEDLINE]

Specific cerebral perfusion patterns in three schizophrenia symptom dimensions.

Tue, 07/31/2018 - 10:40
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Specific cerebral perfusion patterns in three schizophrenia symptom dimensions.

Schizophr Res. 2017 Dec;190:96-101

Authors: Stegmayer K, Strik W, Federspiel A, Wiest R, Bohlhalter S, Walther S

Abstract
Dimensional concepts such as the Research Domain Criteria initiative have been proposed to disentangle the heterogeneity of schizophrenia. One model introduced three neurobiologically informed behavioral dimensions: language, affectivity and motor behavior. To study the brain-behavior associations of these three dimensions, we investigated whether current behavioral alterations were linked to resting state perfusion in distinct brain circuits in schizophrenia. In total, 47 patients with schizophrenia spectrum disorders and 44 healthy controls were included. Psychopathology was assessed with the Positive And Negative Syndrome Scale and the Bern Psychopathology scale (BPS). The BPS provides severity ratings of three behavioral dimensions (language, affectivity and motor). Patients were classified according to the severity of alterations (severe, mild, no) in each dimension. Whole brain resting state cerebral blood flow (CBF) was compared between patient subgroups and controls. Two symptom dimensions were associated with distinct CBF changes. Behavioral alterations in the language dimension were linked to increased CBF in Heschl's gyrus. Altered affectivity was related to increased CBF in amygdala. The ratings of motor behavior instead were not specifically associated with CBF. Investigating behavioral alterations in three schizophrenia symptom dimensions identified distinct regional CBF changes in the language and limbic brain circuits. The results demonstrate a hitherto unknown segregation of pathophysiological pathways underlying a limited number of specific symptom dimensions in schizophrenia.

PMID: 28320578 [PubMed - indexed for MEDLINE]

31 P magnetization transfer magnetic resonance spectroscopy: Assessing the activation induced change in cerebral ATP metabolic rates at 3 T.

Tue, 07/31/2018 - 10:40
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31 P magnetization transfer magnetic resonance spectroscopy: Assessing the activation induced change in cerebral ATP metabolic rates at 3 T.

Magn Reson Med. 2018 Jan;79(1):22-30

Authors: Chen C, Stephenson MC, Peters A, Morris PG, Francis ST, Gowland PA

Abstract
PURPOSE: In vivo 31 P magnetic resonance spectroscopy (MRS) magnetization transfer (MT) provides a direct measure of neuronal activity at the metabolic level. This work aims to use functional 31 P MRS-MT to investigate the change in cerebral adenosine triphosphate (ATP) metabolic rates in healthy adults upon repeated visual stimuli.
METHODS: A magnetization saturation transfer sequence with narrowband selective saturation of γ-ATP was developed for 31 P MT experiments at 3 T.
RESULTS: Using progressive saturation of γ-ATP, the intrinsic T1 relaxation times of phosphocreatine (PCr) and inorganic phosphate (Pi) at 3 T were measured to be 5.1 ± 0.8 s and 3.0 ± 1.4 s, respectively. Using steady-state saturation of γ-ATP, a significant 24% ± 14% and 11% ± 7% increase in the forward creatine kinase (CK) pseudo-first-order reaction rate constant, k1 , was observed upon visual stimulation in the first and second cycles, respectively, of a paradigm consisting of 10-minute rest followed by 10-minute stimulation, with the measured baseline k1 being 0.35 ± 0.04 s-1 . No significant changes in forward ATP synthase reaction rate, PCr/γ-ATP, Pi/γ-ATP, and nicotinamide adenine dinucleotide/γ-ATP ratios, or intracellular pH were detected upon stimulation.
CONCLUSION: This work demonstrates the potential of studying cerebral bioenergetics using functional 31 P MRS-MT to determine the change in the forward CK reaction rate at 3 T. Magn Reson Med 79:22-30, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

PMID: 28303591 [PubMed - indexed for MEDLINE]

Cerebellum and cognition in progressive MS patients: functional changes beyond atrophy?

Mon, 07/30/2018 - 16:00
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Cerebellum and cognition in progressive MS patients: functional changes beyond atrophy?

J Neurol. 2018 Jul 28;:

Authors: Cocozza S, Pontillo G, Russo C, Russo CV, Costabile T, Pepe A, Tedeschi E, Lanzillo R, Brescia Morra V, Brunetti A, Inglese M, Petracca M

Abstract
BACKGROUND: The cerebellum is a predilection site of pathology in progressive multiple sclerosis (PMS) patients, contributing to cognitive deficits. Aim of this study was to investigate lobular cerebellar functional connectivity (FC) in PMS patients in relation to cognition.
METHODS: In this cross-sectional study, resting state fMRI analysis was carried out on 29 PMS patients (11 males, mean age 51.2 ± 11.9 years) and 22 age- and sex-matched healthy controls (HC) (11 males, mean age 49.6 ± 8.8 years). Data were analyzed with a seed-based approach, with four different seeds placed at the level of cerebellar Lobule VI, Crus I, Crus II and Lobule VIIb, accounting for cerebellar structural damage. Cognitive status was assessed with the BICAMS battery. Correlations between fMRI data and clinical variables were probed with the Spearman correlation coefficient.
RESULTS: When testing FC differences between PMS and HC without taking into account cerebellar structural damage, PMS patients showed a reduction of FC between Crus II/Lobule VIIb and the right frontal pole (p = 0.001 and p = 0.002, respectively), with an increased FC between Lobule VIIb and the right precentral gyrus (p < 0.001). After controlling for structural damage, PMS patients still showed a reduced FC between Crus II and right frontal pole (p = 0.005), as well as an increased FC between Lobule VIIb and right precentral gyrus (p = 0.003), with the latter showing an inverse correlation with BVMT scores (r = - 0.393; p = 0.03).
CONCLUSION: PMS patients show cerebellar FC rearrangements that are partially independent from cerebellar structural damage, and are likely expression of a maladaptive functional rewiring.

PMID: 30056570 [PubMed - as supplied by publisher]

Decreased Parietal Beta Power as a Sign of Disease Progression in Patients with Mild Cognitive Impairment.

Mon, 07/30/2018 - 16:00
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Decreased Parietal Beta Power as a Sign of Disease Progression in Patients with Mild Cognitive Impairment.

J Alzheimers Dis. 2018 Jul 21;:

Authors: Sandøe Musaeus C, Schjønning Nielsen M, Nellum Østerbye N, Høgh P

Abstract
BACKGROUND: Electroencephalography (EEG) power has previously been used to compare mild cognitive impairment (MCI) patients who progress to Alzheimer's disease (pMCI) with patients with MCI who remain stable (sMCI) by using beta power. However, the beta band is very broad and smaller frequency bands may improve accuracy.
OBJECTIVE: In the present study, we wanted to investigate whether it was possible to find any differences between pMCI and sMCI using relative power and whether these differences were correlated to cognitive function or neuropathology markers.
METHODS: 17 patients with AD, 27 patients with MCI, and 38 older healthy controls were recruited from two memory clinics and followed for three years. EEGs were recorded at baseline for all participants and relative power was calculated. All participants underwent adjusted batteries of standardized cognitive tests and lumbar puncture.
RESULTS: We found that pMCI showed decreased baseline relative power in the parietal electrodes in the beta1 band (13-17.99 Hz). At 2-year follow-up, we found changes in all baseline beta bands but most pronounced in the beta1 band. In addition, we found that qEEG parietal power was correlated with amyloid-β42 and anterograde memory.
CONCLUSION: These findings suggests that relative power in the parietal electrodes in the beta1 band may be a better way to discriminate between pMCI and sMCI at the time of diagnosis than the broad beta band. Similar findings have also been found with resting state fMRI. In addition, we found that anterograde memory was correlated to qEEG parietal beta1 power.

PMID: 30056426 [PubMed - as supplied by publisher]

Quality of maternal behaviour during infancy predicts functional connectivity between default mode network and salience network 9 years later.

Mon, 07/30/2018 - 16:00
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Quality of maternal behaviour during infancy predicts functional connectivity between default mode network and salience network 9 years later.

Dev Cogn Neurosci. 2018 Jul 21;34:53-62

Authors: Dégeilh F, Bernier A, Leblanc É, Daneault V, Beauchamp MH

Abstract
Infants' experiences are considered to determine to a large degree the strength and effectiveness of neural connections and fine tune the development of brain networks. As one of the most pervasive and potent relational experiences of infancy, parent-child relationships appear to be prime candidates to account for experience-driven differences in children's brain development. Yet, studies linking parenting and functional connectivity are surprisingly scarce, and restricted to the connectivity of limbic structures. Accordingly, this longitudinal study explored whether normative variation in the quality of early maternal behaviour predicts the functional connectivity of large-scale brain networks in late childhood. Maternal mind-mindedness and autonomy support were assessed with 28 children when they were 13 and 15 months old respectively. When children were 10 years of age, children underwent a resting-state functional MRI exam. Functional connectivity was assessed between key regions of the default mode network (DMN), salience network (SN), and frontal-parietal central executive network (CEN). Results revealed that higher mind-mindedness and autonomy support predicted stronger negative connectivity between DMN and SN regions. These findings are the first to provide preliminary evidence suggestive of a long-lasting impact of variation within the normative range of early maternal behaviour on functional connectivity between large-scale brain networks.

PMID: 30056292 [PubMed - as supplied by publisher]

Dissociable effects of sleep deprivation on functional connectivity in the dorsal and ventral default mode networks.

Sun, 07/29/2018 - 15:00
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Dissociable effects of sleep deprivation on functional connectivity in the dorsal and ventral default mode networks.

Sleep Med. 2018 Jun 23;50:137-144

Authors: Chen WH, Chen J, Lin X, Li P, Shi L, Liu JJ, Sun HQ, Lu L, Shi J

Abstract
OBJECTIVE: To examine changes in functional connectivity of the default mode network (DMN) that are induced by sleep deprivation, and to identify individual differences that contribute to the vulnerability of the brain's response to sleep deprivation.
METHODS: Using functional magnetic resonance imaging, we scanned 51 healthy young subjects during the resting state. Of these participants, 28 were scanned following 24 h of sleep deprivation, and 23 age- and education-matched control subjects were scanned after being well rested.
RESULTS: Independent component analysis was conducted to identify the DMN. Unlike previous studies that consider the DMN as one homogeneous network, the present study found a dissociable effect of sleep deprivation on two subsystems of the DMN. Functional connectivity within the dorsal DMN decreased; this was correlated with longer response times in a psychomotor vigilance task (PVT). An enhanced functional connectivity was found within the ventral DMN as well as between two subsystems, after sleep deprivation. In addition, between-subsystems connectivity was positively correlated with working memory and negatively correlated with the response time of PVT, suggesting a possible compensatory effect of enhanced communication across two subsystems.
CONCLUSIONS: The present findings suggest a dissociable effect of sleep deprivation on functional connectivity in the DMN. Lower functional connectivity in dorsal DMN was related to impairments of basic cognitive function. Notably, working memory was positively correlated with the putative compensatory enhanced functional connectivity across two subsystems, which in turn correlated with behavioral performance after sleep deprivation; this suggests that good working memory may play a protective role in sleep deprivation.

PMID: 30055480 [PubMed - as supplied by publisher]

Reading the (functional) writing on the (structural) wall: Multimodal fusion of brain structure and function via a deep neural network based translation approach reveals novel impairments in schizophrenia.

Sun, 07/29/2018 - 15:00
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Reading the (functional) writing on the (structural) wall: Multimodal fusion of brain structure and function via a deep neural network based translation approach reveals novel impairments in schizophrenia.

Neuroimage. 2018 Jul 25;:

Authors: Amin MF, Plis SM, Chekroud A, Hjelm D, Damaraju E, Lee HJ, Bustillo JR, Cho K, Pearlson GD, Calhoun VD

Abstract
This work presents a novel approach to finding linkage/association between multimodal brain imaging data, such as structural MRI (sMRI) and functional MRI (fMRI). Motivated by the machine translation domain, we employ a deep learning model, and consider two different imaging views of the same brain like two different languages conveying some common facts. That analogy enables finding linkages between two modalities. The proposed translation-based fusion model contains a computing layer that learns "alignments" (or links) between dynamic connectivity features from fMRI data and static gray matter patterns from sMRI data. The approach is evaluated on a multi-site dataset consisting of eyes-closed resting state imaging data collected from 298 subjects (age- and gender matched 154 healthy controls and 144 patients with schizophrenia). Results are further confirmed on an independent dataset consisting of eyes-open resting state imaging data from 189 subjects (age- and gender matched 91 healthy controls and 98 patients with schizophrenia). We used dynamic functional connectivity (dFNC) states as the functional features and ICA-based sources from gray matter densities as the structural features. The dFNC states characterized by weakly correlated intrinsic connectivity networks (ICNs) were found to have stronger association with putamen and insular gray matter pattern, while the dFNC states of profuse strongly correlated ICNs exhibited stronger links with the gray matter pattern in precuneus, posterior cingulate cortex (PCC), and temporal cortex. Further investigation with the estimated link strength (or alignment score) showed significant group differences between healthy controls and patients with schizophrenia in several key regions including temporal lobe, and linked these to connectivity states showing less occupancy in healthy controls. Moreover, this novel approach revealed significant correlation between a cognitive score (attention/vigilance) and the function/structure alignment score that was not detected when data modalities were considered separately.

PMID: 30055372 [PubMed - as supplied by publisher]

Functional connectivity of the brain in older women with urgency urinary incontinence.

Sun, 07/29/2018 - 15:00
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Functional connectivity of the brain in older women with urgency urinary incontinence.

Neurourol Urodyn. 2018 Jul 27;:

Authors: Clarkson BD, Karim HT, Griffiths DJ, Resnick NM

Abstract
BACKGROUND: The brain's role in continence is critical but poorly understood. Although regions activated during bladder stimulation have been identified, little is known about the interaction between regions. In this secondary analysis we evaluate resting state and effective connectivity in older women treated for urgency urinary incontinence (UUI).
METHOD: 54 women ≥60 years old with UUI and 10 continent women underwent fMRI scanning during provocation of urinary urgency, both before and after therapy. Response was defined by >50% reduction in leaks on bladder diary. Regions of interest (RoIs) were selected a priori: right insula, medial prefrontal cortex, and dorsal anterior cingulate cortex. Generalized psycho-physiological interaction (gPPI) was used to calculate "effective connectivity" between RoIs during urgency. We performed a one-way ANOVA pre-treatment between groups (continent/responders/non-responders), as well as a two-way mixed ANOVA between group and time (responders/non-responders; pre-/post-therapy) using false discovery rate (FDR) correction. Principal component analysis was used to assess the variance within RoIs. Exploratory voxel-wise connectivity analyses were conducted between each RoI and the rest of the brain.
RESULTS: RoI-RoI connectivity analysis showed connectivity differences between controls, responders, and non-responders, although statistical significance was lost after extensive correction. Principal component analysis confirmed appropriate RoI selection. Voxel-wise analyses showed that connectivity in responders became more like that of controls after therapy (cluster-wise correction P < 0.05). In non-responders, no consistent changes were seen.
CONCLUSION: These data support the postulate that responders and non-responders to therapy may represent different subsets of UUI, one with more of a central etiology, and one without.

PMID: 30054930 [PubMed - as supplied by publisher]

Amygdala connectivity mediates the association between anxiety and depression in patients with major depressive disorder.

Sun, 07/29/2018 - 15:00
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Amygdala connectivity mediates the association between anxiety and depression in patients with major depressive disorder.

Brain Imaging Behav. 2018 Jul 27;:

Authors: He C, Gong L, Yin Y, Yuan Y, Zhang H, Lv L, Zhang X, Soares JC, Zhang H, Xie C, Zhang Z

Abstract
Anxiety is the most frequently co-occurring symptom with depression and subsequently contributes to increased severity and treatment resistance in patients with major depressive disorder (MDD). However, little is known about how these two behaviors are linked or interact at the neural network level. Seventy-five unmedicated MDD patients and 42 cognitively normal (CN) subjects underwent resting-state functional magnetic resonance imaging (R-fMRI) and neuropsychological testing. Multivariate linear regression analysis was performed to investigate the neural substrates of anxiety and depression, as well as their interactive effects on the amygdala functional connectivity (AFC) network in MDD patients. In addition, mediation analysis was employed to explore whether intrinsic amygdala connectivity mediates the association between anxiety and depression in patients with MDD. We found that MDD patients suffered symptoms of severe anxiety and a widely reduced functional connectivity in the AFC network, especially in the frontoparietal system and medial temporal lobe. Furthermore, common and distinct neural circuits involving anxiety and depression were separately identified. Interactive analysis revealed that MDD patients with lower HAMA scores showed milder depressive symptoms and greater AFC strength, while those with higher HAMA scores showed more severe depressive symptoms and lower AFC strength. More importantly, mediation analysis suggested that amygdala connectivity strength mediated the relationship between anxiety and depression in MDD patients. These findings extend our understanding of the brain circuitry implicated in MDD patients with comorbid anxiety, and provide new insight into therapeutic targeting of the neural circuits involved in this comorbidity.

PMID: 30054873 [PubMed - as supplied by publisher]

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