scholarly journals Peripheral inflammation is associated with micro-structural and functional connectivity changes in depression-related brain networks

2021 ◽  
Author(s):  
Manfred G. Kitzbichler ◽  
Athina R. Aruldass ◽  
Gareth J. Barker ◽  
Tobias C. Wood ◽  
Nicholas G. Dowell ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Venous Blood ◽  
Regional Analysis ◽  
Brain Magnetic Resonance Imaging ◽  
Structural Mri ◽  
Posterior Cingulate Cortex ◽  
Proton Density ◽  
Peripheral Inflammation ◽  
Tissue Water ◽  
Weighted Degree

AbstractInflammation is associated with depressive symptoms and innate immune mechanisms are likely causal in some cases of major depression. Systemic inflammation also perturbs brain function and microstructure, though how these are related remains unclear. We recruited N = 46 healthy controls, and N = 83 depressed cases stratified by CRP (> 3 mg/L: N = 33; < 3 mg/L: N = 50). All completed clinical assessment, venous blood sampling for C-reactive protein (CRP) assay, and brain magnetic resonance imaging (MRI). Micro-structural MRI parameters including proton density (PD), a measure of tissue water content, were measured at 360 cortical and 16 subcortical regions. Resting-state fMRI time series were correlated to estimate functional connectivity between individual regions, as well as the sum of connectivity (weighted degree) of each region. Multiple tests for regional analysis were controlled by the false discovery rate (FDR = 5%). We found that CRP was significantly associated with PD in precuneus, posterior cingulate cortex (pC/pCC) and medial prefrontal cortex (mPFC); and with functional connectivity between pC/pCC, mPFC and hippocampus. Depression was associated with reduced weighted degree of pC/pCC, mPFC, and other nodes of the default mode network (DMN). Thus CRP-related increases in proton density—a plausible marker of extracellular oedema—and changes in functional connectivity were anatomically co-localised with DMN nodes that also demonstrated significantly reduced hubness in depression. We suggest that effects of peripheral inflammation on DMN node micro-structure and connectivity may mediate inflammatory effects on depression.

scholarly journals Dysconnectivity of a brain functional network was associated with blood inflammatory markers in depression

2021 ◽  
Author(s):  
Athina R Aruldass ◽  
Manfred G Kitzbichler ◽  
Sarah E Morgan ◽  
Sol Lim ◽  
Mary-Ellen Lynall ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Immune Cells ◽  
Peripheral Blood ◽  
Inflammatory Markers ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Brain Network ◽  
Peripheral Inflammation ◽  
Reactive Protein ◽  
Frontal Operculum

Objective: There is increasing evidence for a subgroup of major depressive disorder (MDD) associated with heightened peripheral blood inflammatory markers. In this study, the authors sought to understand the mechanistic brain-immune axis in inflammation-linked depression by investigating associations between functional connectivity (FC) of brain networks and peripheral inflammation in depression. Methods: Resting-state functional magnetic resonance imaging (fMRI) and peripheral blood immune marker data (C-reactive protein; CRP, interleukin-6; IL-6 and immune cells) were collected on N=46 healthy controls (HC; CRP ≤ 3mg/L) and N=83 cases of MDD, stratified further into low CRP (loCRP MDD; ≤ 3 mg/L; N=50) and high CRP (hiCRP MDD; > 3 mg/L; N=33). In a two-part analysis, network-based statistics (NBS) was firstly performed to ascertain FC differences via HC vs hiCRP MDD comparison. Association between this network of interconnected brain regions and peripheral CRP (N=83), IL-6 (N=72), neutrophils and CD4+ T-cells (N=36) were then examined in MDD cases only. Results: Case-control NBS testing revealed a single network of abnormally attenuated FC in hiCRP MDD, chiefly comprising default mode network (DMN) and ventral attentional network (VA) coupled regions, anatomically connecting the insula/frontal-operculum and posterior cingulate cortex (PCC). Across all MDD cases, FC within the identified network scaled negatively with CRP, IL-6 and neutrophils. Conclusions: The findings suggest that inflammation is associated with attenuation of functional connectivity within a brain network deemed critical for interoceptive signalling, e.g. accurate communication of peripheral bodily signals such as immune states to the brain, with implications for the etiology of inflammation-linked depression. keywords: functional connectivity, network-based statistics, peripheral inflammation, immune cells, depression.

scholarly journals Peripheral inflammation is associated with micro-structural and functional connectivity changes in depression-related brain networks

2020 ◽  
Author(s):  
Manfred G Kitzbichler ◽  
Athina R Aruldass ◽  
Gareth J Barker ◽  
Tobias C Wood ◽  
Nicholas G Dowell ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Depressive Symptoms ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Structural Parameters ◽  
Brain Magnetic Resonance Imaging ◽  
Peripheral Inflammation ◽  
Micro Structure ◽  
Significant Group ◽  
Default Mode

Background: Peripheral inflammation is associated with depressive symptoms and innate immune mechanisms are likely causal for some patients with depression. However, it remains unclear how biomarkers of inflammation in the blood, e.g., C-reactive protein (CRP), relate to the changes in brain micro-structure and function that are hypothesised to mediate effects on depression. Methods: Here, we recruited N=46 healthy controls and N=83 patients with major depressive disorder (MDD), divided into high CRP (>3mg/L; N=33) and low CRP groups (<3mg/L; N=50). All participants completed a clinical assessment, venous blood sampling for CRP, and brain magnetic resonance imaging (MRI). A set of micro-structural parameters including proton density (PD) were estimated at 360 cortical and 16 subcortical regions and fMRI time series correlations used to measure inter-regional functional connectivity and regional weighted degree. Results are reported at stringent whole brain FDR correction (p<0.05). Results: Across participants, CRP showed a significant positive correlation with PD within precuneus / posterior cingulate cortex (pC/pCC) and medial prefrontal cortex (mPFC) and a converse negative correlation within dorsolateral prefrontal cortex (DLPFC). No significant group differences were observed. Functional connectivity analyses demonstrated significant case-control differences centred almost exclusively on the default mode network (DMN), with significantly reduced nodal degree within pC/pCC, mPFC, and temporo-parietal hubs in depressed individuals. Furthermore, high CRP was associated with significantly increased cortico-subcortical connectivity between three key hubs within the DMN: between the hippocampus and both the pC/pCC and mPFC (both of which also showed a positive dependency of PD on CRP), but lower connectivity of DMN (regions p10p, 7m and 31a) and other non-DMN areas to non-DMN sub-cortical regions (putamen and thalamus). Conclusions: Elevated CRP was associated with changes in both cortical micro-structure and subcortical connectivity within key nodes of the default mode network, a network critically implicated in the aetiology of depression, suggesting that effects of peripheral inflammation on pC/pCC and mPFC micro-structure may cause depressive symptoms by differentially modulating their cortico-subcortical connectivity to areas within and outside of the DMN.

scholarly journals Resting State Functional Connectivity Alterations in Individuals with Autism Spectrum Disorders: A Systematic Review

2021 ◽  
Author(s):  
Varun Kumar ◽  
Rahul Garg
Keyword(s):  
Autism Spectrum Disorder ◽  
Functional Connectivity ◽  
Resting State ◽  
Brain Magnetic Resonance Imaging ◽  
Posterior Cingulate Cortex ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Typically Developing ◽  
Resting State Functional Connectivity ◽  
Machine Readable

Many studies investigate the alterations in resting state functional connectivity in autism. Most of these studies focus on different regions of the brain to find the connectivity differ- ences between autism spectrum disorder and typically developing populations. The present review quantitatively extracts this data from all the seed based studies on autism spectrum disorder and uses it to build, for the first time, an Autism Altered Functional Connectome (AAFC) which summarizes the alterations in functional connectivity consistently reported in the literature. The data extracted from all the studies matching the inclusion criteria are presented at one place in human as well as a machine-readable format for further interpretation and analysis. Systematically reviewing 41 publications on 2818 subjects comprising 1459 typically developing and 1359 subjects with autism spectrum disorder, a total of 932 altered functional connectivity links were employed to construct an AAFC. The AAL atlas mapping of these links resulted in 71 replicated links of which 49 were consistent, and 574 unreplicated links that were reported just once. Out of 49, 38 were replicated across different non overlapping datasets. Majority of the studies analyzed the functional connectivity of the Default Mode Network (DMN) and its regions. Two important DMN regions, namely precuneus and posterior cingulate cortex were reported to exhibit different connectivity profiles with former majorly underconnected and later majorly overconnected consistently reported across multiple studies. After mapping the AAFLs to an atlas of brain networks, poor integration within DMN regions, and poor segregation of DMN regions with extra-DMN regions was observed. Keywords: Connectome, Autism Spectrum Disorder, Brain, Magnetic Resonance Imaging

scholarly journals Effect of a One-Week Spiritual Retreat on Brain Functional Connectivity: A Preliminary Study

Religions ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Nancy A. Wintering ◽  
David B. Yaden ◽  
Christopher Conklin ◽  
Mahdi Alizadeh ◽  
Feroze B. Mohamed ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Parietal Lobe ◽  
Well Being ◽  
Posterior Cingulate Cortex ◽  
Spiritual Well Being ◽  
Spiritual Retreat ◽  
Baseline Evaluation ◽  
Preliminary Study ◽  
Brain Functional Connectivity ◽  
Spiritual Impact

Background: Many individuals participate in spiritual retreats to enhance their sense of spirituality or to improve their overall mental and spiritual well-being. We are not aware of any studies specifically evaluating changes in functional connectivity using functional magnetic resonance imaging (fMRI) in individuals undergoing an intense spiritual retreat program. The goal of this study was to determine whether such changes occur as a result of participating in the Spiritual Exercises of St. Ignatius. Methods: We conducted psychological and spiritual measures in conjunction with functional connectivity analysis of fMRI in 14 individuals prior to and following shortly after their participation in a one-week spiritual retreat. Results: Significant changes in functional connectivity were observed after the retreat program, compared to baseline evaluation, particularly in the posterior cingulate cortex, pallidum, superior frontal lobe, superior parietal lobe, superior and inferior temporal lobe, and the cerebellum. Significant changes in a variety of psychological and spiritual measures were identified as result of participation in the retreat. Conclusion: Overall, these preliminary findings suggest that this intensive spiritual retreat resulted in significant changes in brain functional connectivity, and warrants further investigation to evaluate the physiological, psychological, and spiritual impact of these changes.

scholarly journals Neural basis underlying the trait of attachment anxiety and avoidance revealed by the amplitude of low-frequency fluctuations and resting-state functional connectivity

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Min Deng ◽  
Xing Zhang ◽  
Xiaoyan Bi ◽  
Chunhai Gao
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Low Frequency ◽  
Cingulate Cortex ◽  
Posterior Cingulate Cortex ◽  
Attachment Anxiety ◽  
Frequency Fluctuation ◽  
Resting State Functional Connectivity ◽  
Attachment Avoidance ◽  
Posterior Cingulate

Abstract Background Attachment theory demonstrates that early attachment experience shapes internal working models with mental representations of self and close relationships, which affects personality traits and interpersonal relationships in adulthood. Although research has focused on brain structural and functional underpinnings to disentangle attachment styles in healthy individuals, little is known about the spontaneous brain activity associated with self-reported attachment anxiety and avoidance during the resting state. Methods One hundred and nineteen individuals participated in the study, completing the Experience in Close Relationship scale immediately after an 8-min fMRI scanning. We used the resting-state functional magnetic resonance imaging (rs-fMRI) signal of the amplitude of low-frequency fluctuation and resting-state functional connectivity to identify attachment-related regions and networks. Results Consequently, attachment anxiety is closely associated with the amplitude of low-frequency fluctuations in the right posterior cingulate cortex, over-estimating emotional intensity and exaggerating outcomes. Moreover, the functional connectivity between the posterior cingulate cortex and fusiform gyrus increases detection ability for potential threat or separation information, facilitating behavior motivation. The attachment avoidance is positively correlated with the amplitude of low-frequency fluctuation in the bilateral lingual gyrus and right postcentral and negatively correlated with the bilateral orbital frontal cortex and inferior temporal gyrus. Functional connection with attachment avoidance contains critical nodes in the medial temporal lobe memory system, frontal-parietal network, social cognition, and default mode network necessary to deactivate the attachment system and inhibit attachment-related behavior. Conclusion and implications These findings clarify the amplitude of low-frequency fluctuation and resting-state functional connectivity neural signature of attachment style, associated with attachment strategies in attachment anxiety and attachment avoidance individuals. These findings may improve our understanding of the pathophysiology of the attachment-related disorder.

scholarly journals Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: a case study

2018 ◽  
Author(s):  
Christiane Oedekoven ◽  
James L. Keidel ◽  
Stuart Anderson ◽  
Angus Nisbet ◽  
Chris Bird
Keyword(s):  
Functional Connectivity ◽  
Episodic Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Structural Mri ◽  
Brain Regions ◽  
Left Hippocampus ◽  
Cortical Regions ◽  
The Right ◽  
Encoding And Retrieval

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.

scholarly journals Dynamic Alterations in Neural Networks Supporting Aversive Learning in Children Exposed to Trauma: Neural Mechanisms Underlying Psychopathology

2020 ◽  
Author(s):  
Stephanie N. DeCross ◽  
Kelly Sambrook ◽  
Margaret Sheridan ◽  
Nim Tottenham ◽  
Katie A McLaughlin
Keyword(s):  
Functional Connectivity ◽  
Temporal Dynamics ◽  
Longitudinal Design ◽  
Region Of Interest ◽  
Posterior Cingulate Cortex ◽  
Parahippocampal Gyrus ◽  
Functional Coupling ◽  
Neural Activation ◽  
Aversive Learning ◽  
Frontal Pole

Altered aversive learning represents a potential mechanism through which childhood trauma (CT) might influence risk for psychopathology. This study examines the temporal dynamics of neural activation and patterns of functional connectivity during aversive learning in children with and without CT, and evaluates whether these neural patterns mediate the association of CT with psychopathology in a longitudinal design. 147 children (aged 8-16 years, 77 with CT) completed a fear conditioning procedure during an fMRI scan. Dynamic patterns of neural activation were examined in whole-brain and region-of-interest analyses; functional connectivity was assessed with generalized psychophysiological interaction analyses. We evaluated whether the associations between CT and psychopathology symptoms at baseline and two-year follow-up were mediated by neural activation and connectivity during aversive learning. Children exposed to trauma displayed blunted patterns of neural activation over time during CS+&gt;CS- in right amygdala and during CS-&gt;CS+ in right hippocampus and frontal pole. Additionally, during CS+&gt;CS-, CT was associated with elevated functional connectivity of right amygdala with fronto-parietal regions and reduced connectivity with hippocampus, posterior parahippocampal gyrus, and posterior cingulate cortex. The longitudinal association between CT and later externalizing symptoms was mediated by blunted activation in right amygdala and insula. Reduced amygdala-hippocampal connectivity mediated the association of CT with transdiagnostic anxiety symptoms. CT is associated with poor threat-safety discrimination and altered functional coupling between salience and default mode network regions during aversive learning. These altered neural dynamics during learning may be key mechanisms linking CT with internalizing and externalizing psychopathology.

scholarly journals A Connectomic Atlas of the Human Cerebrum—Chapter 8: The Posterior Cingulate Cortex, Medial Parietal Lobe, and Parieto-Occipital Sulcus

2018 ◽  
Vol 15 (suppl_1) ◽  
pp. S350-S371 ◽  
Author(s):  
Cordell M Baker ◽  
Joshua D Burks ◽  
Robert G Briggs ◽  
Andrew K Conner ◽  
Chad A Glenn ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Functional Connectivity ◽  
Functional Significance ◽  
Parietal Lobe ◽  
Structural Connectivity ◽  
Cingulate Cortex ◽  
Posterior Cingulate Cortex ◽  
Posterior Cingulate ◽  
Human Connectome Project

ABSTRACT In this supplement, we build on work previously published under the Human Connectome Project. Specifically, we seek to show a comprehensive anatomic atlas of the human cerebrum demonstrating all 180 distinct regions comprising the cerebral cortex. The location, functional connectivity, and structural connectivity of these regions are outlined, and where possible a discussion is included of the functional significance of these areas. In part 8, we specifically address regions relevant to the posterior cingulate cortex, medial parietal lobe, and the parieto-occipital sulcus.

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