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Rude mechanicals in brain haemodynamics: non-neural actors that influence blood flow.

Wed, 11/18/2020 - 06:05
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Rude mechanicals in brain haemodynamics: non-neural actors that influence blood flow.

Philos Trans R Soc Lond B Biol Sci. 2021 Jan 04;376(1815):20190635

Authors: Das A, Murphy K, Drew PJ

Abstract
Fluctuations in blood oxygenation and flow are widely used to infer brain activity during resting-state functional magnetic resonance imaging (fMRI). However, there are strong systemic and vascular contributions to resting-state signals that are unrelated to ongoing neural activity. Importantly, these non-neural contributions to haemodynamic signals (or 'rude mechanicals') can be as large as or larger than the neurally evoked components. Here, we review the two broad classes of drivers of these signals. One is systemic and is tied to fluctuations in external drivers such as heart rate and breathing, and the robust autoregulatory mechanisms that try to maintain a constant milieu in the brain. The other class comprises local, active fluctuations that appear to be intrinsic to vascular tissue and are likely similar to active local fluctuations seen in vasculature all over the body. In this review, we describe these non-neural fluctuations and some of the tools developed to correct for them when interpreting fMRI recordings. However, we also emphasize the links between these vascular fluctuations and brain physiology and point to ways in which fMRI measurements can be used to exploit such links to gain valuable information about neurovascular health and about internal brain states. This article is part of the theme issue 'Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity'.

PMID: 33190603 [PubMed - in process]

Callosal anisotropy predicts attentional network changes after parietal inhibitory stimulation.

Tue, 11/17/2020 - 12:05
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Callosal anisotropy predicts attentional network changes after parietal inhibitory stimulation.

Neuroimage. 2020 Nov 12;:117559

Authors: Schintu S, Cunningham CA, Freedberg M, Taylor P, Gotts SJ, Shomstein S, Wassermann EM

Abstract
Hemispatial neglect is thought to result from disruption of interhemispheric equilibrium. Right hemisphere lesions deactivate the right frontoparietal network and hyperactivate the left via release from interhemispheric inhibition. Support for this putative mechanism comes from neuropsychological evidence as well as transcranial magnetic stimulation (TMS) studies in healthy subjects, in whom right posterior parietal cortex (PPC) inhibition causes neglect-like, rightward, visuospatial bias. Concurrent TMS and fMRI after right PPC TMS show task-dependent changes but may fail to identify effects of stimulation in areas not directly activated by the specific task, complicating interpretations. We used resting-state functional connectivity (RSFC) after inhibitory TMS over the right PPC to examine changes in the networks underlying visuospatial attention and used diffusion-weighted imaging to measure the structural properties of relevant white matter pathways. In a crossover experiment in healthy individuals, we delivered continuous theta burst TMS to the right PPC and vertex as control condition. We hypothesized that PPC inhibitory stimulation would result in: a rightward visuospatial bias, decrease frontoparietal RSFC, and increase the PPC RSFC with the attentional network in the left hemisphere. We also expected that individual differences in fractional anisotropy (FA) of the frontoparietal network and the callosal pathway between the PPCs would account for variability of the TMS-induced RSFC changes. As hypothesized, TMS over the right PPC caused a rightward shift in line bisection judgment and increased RSFC between the right PPC and the left superior temporal gyrus. This effect was inversely related to FA in the posterior corpus callosum. Local inhibition of the right PPC reshapes connectivity in the attentional network and depends significantly on interhemispheric connections.

PMID: 33189929 [PubMed - as supplied by publisher]

rest2vec: Vectorizing the resting-state functional connectome using graph embedding.

Tue, 11/17/2020 - 12:05
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rest2vec: Vectorizing the resting-state functional connectome using graph embedding.

Neuroimage. 2020 Nov 11;:117538

Authors: Morrissey ZD, Zhan L, Ajilore O, Leow AD

Abstract
Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used in connectomics for studying the functional relationships between regions of the human brain. rs-fMRI connectomics, however, has inherent analytical challenges, such as how to properly model negative correlations between BOLD time series. In addition, functional relationships between brain regions do not necessarily correspond to their anatomical distance, making the functional topology of the brain less well understood. Recent machine learning techniques, such as word2vec, have used embedding methods to map high-dimensional data into vector spaces, where words with more similar meanings are mapped closer to one another. Inspired by this approach, we have developed the graph embedding pipeline rest2vec for studying the vector space of functional connectomes. We demonstrate how rest2vec uses the phase angle spatial embedding (PhASE) method with dimensionality reduction to embed the connectome into lower dimensions, where the functional definition of a brain region is represented continuously in an intrinsic "functional space." Furthermore, we show how the "functional distance" between brain regions in this space can be applied to discover biologically-relevant connectivity gradients. Interestingly, rest2vec can be conceptualized in the context of the recently proposed maximum mean discrepancy (MMD) metric, followed by a double-centering approach seen in kernel PCA. In sum, rest2vec creates a low-dimensional representation of the rs-fMRI connectome where brain regions are mapped according to their functional relationships, giving a more informed understanding of the functional organization of the brain.

PMID: 33188880 [PubMed - as supplied by publisher]

Frequency-specific altered global signal topography in drug-naïve first-episode patients with adolescent-onset schizophrenia.

Tue, 11/17/2020 - 12:05
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Frequency-specific altered global signal topography in drug-naïve first-episode patients with adolescent-onset schizophrenia.

Brain Imaging Behav. 2020 Nov 13;:

Authors: Wang X, Liao W, Han S, Li J, Wang Y, Zhang Y, Zhao J, Chen H

Abstract
Adolescent-onset schizophrenia (AOS) is a severe neuropsychiatric disease associated with frequency-specific abnormalities across distributed neural systems in a slow rhythm. Recently, functional magnetic resonance imaging (fMRI) studies have determined that the global signal. (GS) is an important source of the local neuronal activity in 0.01-0.1 Hz frequency band. However, it remains unknown whether the effects follow a specific spatially preferential pattern in different frequency bands in schizophrenia. To address this issue, resting-state fMRI data from 39 drug-naïve AOS patients and 31 healthy controls (HCs) were used to assess the changes in GS topography patterns in the slow-4 (0.027-0.073 Hz) and slow-5 bands (0.01-0.027 Hz). Results revealed that GS mainly affects the default mode network (DMN) in slow-4 and sensory regions in the slow-5 band respectively, and GS has a stronger driving effect in the slow-5 band. Moreover, significant frequency-by-group interaction was observed in the frontoparietal network. Compared with HCs, patients with AOS exhibited altered GS topography mainly located in the DMN. Our findings demonstrated that the influence of the GS on brain networks altered in a frequency-specific way in schizophrenia.

PMID: 33188473 [PubMed - as supplied by publisher]

Aberrant striatal coupling with default mode and central executive network relates to self-reported avolition and anhedonia in schizophrenia.

Tue, 11/17/2020 - 12:05
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Aberrant striatal coupling with default mode and central executive network relates to self-reported avolition and anhedonia in schizophrenia.

J Psychiatr Res. 2020 Nov 04;:

Authors: Brakowski J, Manoliu A, Homan P, Bosch O, Herdener M, Seifritz E, Kaiser S, Kirschner M

Abstract
BACKGROUND: Avolition and anhedonia are common symptoms in schizophrenia and are related to poor long-term prognosis. There is evidence for aberrant cortico-striatal function and connectivity as neural substrate of avolition and anhedonia. However, it remains unclear how both relate to shared or distinct striatal coupling with large-scale intrinsic networks. Using resting state functional magnetic resonance imaging (rs-fMRI) this study investigated the association of large-scale cortico-striatal functional connectivity with self-reported and clinician-rated avolition and anhedonia in subjects with schizophrenia.
METHODS: Seventeen subjects with schizophrenia (SZ) and 28 healthy controls (HC) underwent rs-fMRI. Using Independent Component Analysis (ICA), we assessed Independent Components (ICs) reflecting intrinsic connectivity networks (ICNs), intra intrinsic functional connectivity within the ICs (intra-iFC), and intrinsic functional connectivity between different ICs (inter-iFC). Avolition and anhedonia were assessed using the Self Evaluation Scale for Negative Symptoms and the Brief Negative Symptom Scale.
RESULTS: ICA revealed three striatal components and six cortical ICNs. Both self-rated avolition and anhedonia correlated with increased inter-iFC between the caudate and posterior Default Mode Network (pDMN) and between the caudate and Central Executive Network (CEN). In contrast, clinician-rated avolition and anhedonia were not correlated with cortico-striatal connectivity. Group comparison revealed trend-wise decreased inter-iFC between the caudate and Salience Network (SN) in schizophrenia patients compared to HC.
DISCUSSION: Self-rated, but not clinician-rated, avolition and anhedonia was associated with aberrant striatal coupling with the default mode and the central executive network. These findings suggest that self-reported and clinician-rated scores might capture different aspects of motivational and hedonic deficits in schizophrenia and therefore relate to different cortico-striatal functional abnormalities.

PMID: 33187692 [PubMed - as supplied by publisher]

Increased Dynamic Flexibility in the Medial Temporal Lobe Network Following an Exercise Intervention Mediates Generalization of Prior Learning.

Tue, 11/17/2020 - 12:05
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Increased Dynamic Flexibility in the Medial Temporal Lobe Network Following an Exercise Intervention Mediates Generalization of Prior Learning.

Neurobiol Learn Mem. 2020 Nov 10;:107340

Authors: Sinha N, Berg CN, Yassa MA, Gluck MA

Abstract
Recent work has conceptualized the brain as a network comprised of groups of sub-networks or modules. "Flexibility" of brain network(s) indexes the dynamic reconfiguration of comprising modules. Using novel techniques from dynamic network neuroscience applied to high-resolution resting-state functional magnetic resonance imaging (fMRI), the present study investigated the effects of an aerobic exercise intervention on the dynamic rearrangement of modular community structure-the measure of neural flexibility-within the medial temporal lobe (MTL) network. The MTL is one of the earliest brain regions impacted by Alzheimer's disease. It is also a major site of neuroplasticity that is sensitive to the effects of exercise. In a two-group non-randomized, repeated measures and matched control design with 34 healthy older adults, we observed an exercise-related increase in flexibility within the MTL network. Furthermore, MTL network flexibility mediated the beneficial effect aerobic exercise had on mnemonic flexibility, measured by the ability to generalize past learning to novel task demands. Our results suggest that exercise exerts a rehabilitative and protective effect on MTL function, resulting in dynamically evolving networks of regions that interact in complex communication patterns. These reconfigurations may underlie exercise-induced improvements on cognitive measures of generalization, which are sensitive to subtle changes in the MTL.

PMID: 33186745 [PubMed - as supplied by publisher]

Tracking Resting-state Functional Connectivity Changes and Mind Wandering: A Longitudinal Neuroimaging Study.

Tue, 11/17/2020 - 12:05
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Tracking Resting-state Functional Connectivity Changes and Mind Wandering: A Longitudinal Neuroimaging Study.

Neuropsychologia. 2020 Nov 10;:107674

Authors: He H, Li Y, Chen Q, Wei D, Shi L, Wu X, Qiu J

Abstract
Mind wandering (MW) refers to a drift of attention away from the ongoing events to internal concerns and activates brain regions in the default mode network (DMN) and the frontoparietal control network (FPCN). Although a number of studies using rest-fMRI data have shown that static and dynamic functional connectivity within the DMN were related to individual variations in self-reported MW, whether the brain functional connectivity could predict MW remained unclear. Here, we carried out longitudinal data collection from 122 participants that underwent three times of MRI scans and simultaneously completed self-reported MW scales over the course of two years to clarify whether a direct relationship existed between brain functional connectivity and MW. We identified 16 functional connectivity involving the DMN and FPCN that were consistently and stably associated with MW across the three time points. However, there were only significant cross-lagged effects between DMN-involved connections and MW frequency rather than FPCN-involved connections. In addition, the results indicated that the mean value of functional connectivity involving the DMN (FC-DMN) in the low stable (LS) group was the weakest, followed by mean connectivity in the moderate increasing (MI) group and mean connectivity in the high stable (HS) group. These results support previous research linking MW with connections between partial areas involving the DMN and FPCN. Importantly, our findings indicated that brain functional connectivity involving DMN predicted the subsequent MW and provided further support for the trait-based nature of MW.

PMID: 33186573 [PubMed - as supplied by publisher]

Impact of self-designed Ningxin Anshen Decoction on the resting-state network functional connectivity in patients with mild to moderate generalized anxiety disorders.

Tue, 11/17/2020 - 12:05
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Impact of self-designed Ningxin Anshen Decoction on the resting-state network functional connectivity in patients with mild to moderate generalized anxiety disorders.

Ann Palliat Med. 2020 Oct 27;:

Authors: He W, Xiong H, Fang J, Gu H

Abstract
BACKGROUND: Generalized anxiety disorder (GAD) is a persistent chronic excessive anxiety that is hard to control. Our previous study indicated that self-designed Ningxin Anshen Formula (NXAS) was effective to treat mild to moderate GAD patients. This study is a randomized controlled clinical trial and aimed to investigate the imapct of self-designed NXAS on the resting-state functional connectivity (rsFC) in patients with mild to moderate GAD and explore the potential mechanisms.
METHODS: A total of 61 patients diagnosed with mild to moderate GAD were recruited and divided into two groups randomly: NXAS group (n=31) and placebo group (n=30). Before and after treatment, the rsFC was examined by resting-state functional MRI (rs-fMRI), the anxiety was assessed with HAMA, and the independent component analysis (ICA) was used to analyze the resting-state functional connectivity (rsFC). The correlation between HAMA score and abnormal rsFC was further evaluated.
RESULTS: The default mode network (DMN) showed evident rsFC interaction in the PCUN in both groups before and after therapy. The salience network (SN) showed obvious rsFC interaction in the bilateral gyrus frontalis inferiors and bilateral gyri temporalis superiors before and after therapy. In the NXAS group, the rsFC interction reduced significantly in the left gyrus frontalis inferior, but remained unchanged in the right gyrus frontalis inferior and bilateral gyri temporalis superiors after therapy. In the control group, the rsFC interaction increased dramatically after treatment. In addition, the abnormal rsFC had no relationship with HAMA score.
CONCLUSIONS: The self-designed NXAS can increase the rsFC in the PUCN on DMN and reduce rsFC in the orbIFG.L on SN to exert anti-anxiety effect.

PMID: 33183032 [PubMed - as supplied by publisher]

Resting-state default mode network connectivity in young individuals with Down syndrome.

Sat, 11/14/2020 - 00:00
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Resting-state default mode network connectivity in young individuals with Down syndrome.

Brain Behav. 2020 Nov 12;:e01905

Authors: Figueroa-Jimenez MD, Cañete-Massé C, Carbó-Carreté M, Zarabozo-Hurtado D, Peró-Cebollero M, Salazar-Estrada JG, Guàrdia-Olmos J

Abstract
BACKGROUND: Down syndrome (DS) is a chromosomal disorder that causes intellectual disability. Few studies have been conducted on functional connectivity using resting-state fMRI (functional magnetic resonance imaging) signals or more specifically, on the relevant structure and density of the default mode network (DMN). Although data on this issue have been reported in adult DS individuals (age: >45 years), the DMN properties in young DS individuals have not been studied. The aim of this study was to describe the density and structure of the DMN network from fMRI signals in young DS (age: <36 years).
METHOD: A sample of 22 young people with DS between the ages of 16 and 35 (M = 25.5 and SD = 5.1) was recruited in various centers for people with intellectual disability (ID). In addition to sociodemographic data, a six-minute fMRI session was recorded with a 3. T Philips Ingenia scanner. A control group of 22 young people, matched by age and gender, was obtained from the Human Connectome Project (to compare the networks properties between groups).
RESULTS: The values of the 48 ROIs that configured the DMN were obtained, and the connectivity graphs for each subject, the average connectivity graph for each group, the clustering and degree values for each ROI, and the average functional connectivity network were estimated.
CONCLUSIONS: A higher density of overactivation was identified in DS group in the ventral, sensorimotor, and visual DMN networks, although within a framework of a wide variability of connectivity patterns in comparison with the control group network. These results extend our understanding of the functional connectivity networks pattern and intrasubject variability in DS.

PMID: 33179859 [PubMed - as supplied by publisher]

Altered Functional Network Associated With Cognitive Performance in Early Parkinson Disease Measured by Eigenvector Centrality Mapping.

Sat, 11/14/2020 - 00:00
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Altered Functional Network Associated With Cognitive Performance in Early Parkinson Disease Measured by Eigenvector Centrality Mapping.

Front Aging Neurosci. 2020;12:554660

Authors: Cao F, Guan X, Ma Y, Shao Y, Zhong J

Abstract
Objective: To investigate relationships between whole-brain functional changes and the performance of multiple cognitive functions in early Parkinson's disease (PD). Methods: In the current study, we evaluated resting-state functional MRI (rsfMRI) data and neuropsychological assessments for various cognitive functions in a cohort with 84 early PD patients from the Parkinson's Progression Markers Initiative (PPMI). Eigenvector centrality (EC) mapping based on rsfMRI was used to identify the functional connectivity of brain areas correlated with different neuropsychological scores at a whole-brain level. Results: Our study demonstrated that in the early PD patients, scores of Letter Number Sequencing (LNS) were positively correlated with EC in the left inferior occipital gyrus (IOG) and lingual gyrus. The immediate recall scores of Hopkins Verbal Learning Test-Revised (HVLT-R) were positively correlated with EC in the left superior frontal gyrus. No correlation was found between the EC and other cognitive performance scores. Conclusions: Functional alternations in the left occipital lobe (inferior occipital and lingual gyrus) and left superior frontal gyrus may account for the performance of working memory and immediate recall memory, respectively in early PD. These results may broaden the understanding of the potential mechanism of cognitive impairments in early PD.

PMID: 33178007 [PubMed]

Positive association between serum quinolinic acid and functional connectivity following concussion.

Fri, 11/13/2020 - 05:59
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Positive association between serum quinolinic acid and functional connectivity following concussion.

Brain Behav Immun. 2020 Nov 08;:

Authors: Meier TB, España L, Nitta ME, Kent Teague T, Brett BL, Nelson LD, McCrea MA, Savitz J

Abstract
The molecular mechanisms underlying the diverse psychiatric and neuropathological sequalae documented in subsets of athletes with concussion have not been identified. We have previously reported elevated quinolinic acid (QuinA), a neurotoxic kynurenine pathway metabolite, acutely following concussion in football players with prior concussion. Similarly, work from our group and others has shown that increased functional connectivity strength, assessed using resting state fMRI, occurs following concussion and is associated with worse concussion-related symptoms and outcome. Moreover, other work has shown that repetitive concussion may have cumulative effects on functional connectivity and is a risk factor for adverse outcomes. Understanding the molecular mechanisms underlying these cumulative effects may ultimately be important for therapeutic interventions or the development of prognostic biomarkers. Thus, in this work, we tested the hypothesis that the relationship between QuinA in serum and functional connectivity following concussion would depend on the presence of a prior concussion. Concussed football players with prior concussion (N=21) and without prior concussion (N=16) completed a MRI session and provided a blood sample at approximately 1 days, 8 days, 15 days, and 45 days post-injury. Matched, uninjured football players with (N=18) and without prior concussion (N=24) completed similar visits. The association between QuinA and global connectivity strength differed based on group (F(3, 127)=3.46, p=0.019); post-hoc analyses showed a positive association between QuinA and connectivity strength in concussed athletes with prior concussion (B=16.05, SE = 5.06, p=0.002, 95%CI[6.06, 26.03]), but no relationship in concussed athletes without prior concussion or controls. Region-specific analyses showed that this association was strongest in bilateral orbitofrontal cortices, insulae, and basal ganglia. Finally, exploratory analyses found elevated global connectivity strength in concussed athletes with prior concussion who reported depressive symptoms at the 1-day visit compared to those who did not report depressive symptoms (t(15)=2.37, mean difference=13.50, SE=5.69, p=0.032, 95%CI[1.36, 25.63], Cohen's d =1.15.). The results highlight a potential role of kynurenine pathway (KP) metabolites in altered functional connectivity following concussion and raise the possibility that repeated concussion has a "priming" effect on KP metabolism.

PMID: 33176183 [PubMed - as supplied by publisher]

Altered Resting State Brain Networks and Cognition in Familial Adenomatous Polyposis.

Fri, 11/13/2020 - 05:59
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Altered Resting State Brain Networks and Cognition in Familial Adenomatous Polyposis.

medRxiv. 2020 Nov 04;:

Authors: Cali RJ, Nephew BC, Moore CM, Chumachenko S, Sala AC, Cintron B, Luciano C, King JA, Hooper SR, Giardiello FM, Cruz-Correa M

Abstract
Familial Adenomatous Polyposis (FAP) is an autosomal dominant disorder caused by mutation of the APC gene presenting with numerous colorectal adenomatous polyps and a near 100% risk of colon cancer. Preliminary research findings from our group indicate that FAP patients experience significant deficits across many cognitive domains. In the current study, fMRI brain metrics in a FAP population and matched controls were used to further the mechanistic understanding of reported cognitive deficits. This research identified and characterized any possible differences in resting brain networks and associations between neural network changes and cognition from 34 participants (18 FAP patients, 16 healthy controls). Functional connectivity analysis was performed using FSL with independent component analysis (ICA) to identify functional networks. Significant differences between cases and controls were observed in 8 well-established resting state networks. With the addition of an aggregate cognitive measure as a covariate, these differences were virtually non-existent, indicating a strong correlation between cognition and brain activity at the network level. The data indicate robust and pervasive effects on functional neural network activity among FAP patients and these effects are likely involved in cognitive deficits associated with this disease.

PMID: 33173924 [PubMed]

Brain Activations and Functional Connectivity Patterns Associated with Insight-Based and Analytical Anagram Solving.

Fri, 11/13/2020 - 05:59
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Brain Activations and Functional Connectivity Patterns Associated with Insight-Based and Analytical Anagram Solving.

Behav Sci (Basel). 2020 Nov 08;10(11):

Authors: Sinitsyn DO, Bakulin IS, Poydasheva AG, Legostaeva LA, Kremneva EI, Lagoda DY, Chernyavskiy AY, Medyntsev AA, Suponeva NA, Piradov MA

Abstract
Insight is one of the most mysterious problem-solving phenomena involving the sudden emergence of a solution, often preceded by long unproductive attempts to find it. This seemingly unexplainable generation of the answer, together with the role attributed to insight in the advancement of science, technology and culture, stimulate active research interest in discovering its neuronal underpinnings. The present study employs functional Magnetic resonance imaging (fMRI) to probe and compare the brain activations occurring in the course of solving anagrams by insight or analytically, as judged by the subjects. A number of regions were activated in both strategies, including the left premotor cortex, left claustrum, and bilateral clusters in the precuneus and middle temporal gyrus. The activated areas span the majority of the clusters reported in a recent meta-analysis of insight-related fMRI studies. At the same time, the activation patterns were very similar between the insight and analytical solutions, with the only difference in the right sensorimotor region probably explainable by subject motion related to the study design. Additionally, we applied resting-state fMRI to study functional connectivity patterns correlated with the individual frequency of insight anagram solutions. Significant correlations were found for the seed-based connectivity of areas in the left premotor cortex, left claustrum, and left frontal eye field. The results stress the need for optimizing insight paradigms with respect to the accuracy and reliability of the subjective insight/analytical solution classification. Furthermore, the short-lived nature of the insight phenomenon makes it difficult to capture the associated neural events with the current experimental techniques and motivates complementing such studies by the investigation of the structural and functional brain features related to the individual differences in the frequency of insight-based decisions.

PMID: 33171616 [PubMed]

High schizotypy traits are associated with reduced hippocampal resting state functional connectivity.

Wed, 11/11/2020 - 23:57
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High schizotypy traits are associated with reduced hippocampal resting state functional connectivity.

Psychiatry Res Neuroimaging. 2020 Oct 21;:111215

Authors: P K, F S, A D, P A

Abstract
Altered hippocampal functioning is proposed to play a critical role in the development of schizophrenia-spectrum disorders. Previous resting state functional Magnetic Resonance Imaging (rs-fMRI) studies report disrupted hippocampal connectivity in patients with psychosis and in individuals with clinical high risk, yet hippocampal connectivity has not been investigated in people with high schizotypy traits. Here we used rs-fMRI to examine hippocampal connectivity in healthy people with low (LS, n = 23) and high levels (HS, n = 22) of schizotypal traits assessed using the Schizotypy Personality Questionnaire. Using a bilateral hippocampal seed region, we examined resting state functional connectivity (RSFC) between hippocampus and striatal, thalamic and prefrontal cortex regions of interest. Compared to LS, HS participants showed lower RSFC between hippocampus and striatum and between hippocampus and thalamus. Whilst the group effect of reduced hippocampal RSFC in striatal and thalamic regions was driven by total schizotypy scores, positive schizotypy subfactor scores were significantly positively correlated with hippocampus-caudate/thalamus RSFC. Group differences in RSFC were not observed between hippocampus and prefrontal cortex. These results demonstrate that subclinical schizotypal traits are associated with altered hippocampal connectivity in striatal and thalamic regions and provide further support that hippocampal dysconnectivity confers risk for schizophrenia spectrum disorders.

PMID: 33168329 [PubMed - as supplied by publisher]

Exploration of Functional Connectivity Changes Previously Reported in Fibromyalgia and Their Relation to Psychological Distress and Pain Measures.

Wed, 11/11/2020 - 23:57
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Exploration of Functional Connectivity Changes Previously Reported in Fibromyalgia and Their Relation to Psychological Distress and Pain Measures.

J Clin Med. 2020 Nov 05;9(11):

Authors: van Ettinger-Veenstra H, Boehme R, Ghafouri B, Olausson H, Wicksell RK, Gerdle B

Abstract
Neural functional connectivity changes in the default mode network (DMN), Central executive network (CEN), and insula have been implicated in fibromyalgia (FM) but stem from a sparse set of small-scale studies with limited power for the investigation of confounding effects. We investigated whether anxiety, depression, pain sensitivity, and pain intensity modulated functional connectivity related to DMN nodes, CEN nodes, and insula. Resting-state functional magnetic resonance imaging data were collected from 31 females with FM and 28 age-matched healthy controls. Connectivity was analysed with a region-based connectivity analysis between DMN nodes in ventromedial prefrontal cortex (vmPFC) and posterior cingulate cortex, CEN nodes in the intraparietal sulcus (IPS), and bilateral insula. FM patients displayed significantly higher levels of anxiety and depressive symptoms than controls. The right IPS node of the CEN showed a higher level of connectivity strength with right insula in FM with higher pain intensity compared to controls. More anxiety symptoms in FM correlated with higher levels of connectivity strength between the vmPFC DMN node and right sensorimotor cortex. These findings support the theory of altered insular connectivity in FM and also suggest altered IPS connectivity in FM. Interestingly, no change in insular connectivity with DMN was observed.

PMID: 33167371 [PubMed]