scholarly journals Aberrant Interhemispheric Functional Connectivity in Diabetic Retinopathy Patients

2021 ◽  
Vol 15 ◽  
Author(s):  
Song Wan ◽  
Wen Qing Xia ◽  
Yu Lin Zhong
Keyword(s):  
Diabetic Retinopathy ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Coordination Pattern ◽  
Precentral Gyrus ◽  
Default Mode ◽  
Sensorimotor Network ◽  
Visual Network

Background: Accumulating lines of evidence demonstrated that diabetic retinopathy (DR) patients trigger abnormalities in brain’s functional connectivity (FC), whereas the alterations of interhemispheric coordination pattern occurring in DR are not well understood. Our study was to investigate alterations of interhemispheric coordination in DR patients.Methods: Thirty-four DR individuals (19 males and 15 females: mean age: 52.97 ± 8.35 years) and 37 healthy controls (HCs) (16 males and 21 females; mean age: 53.78 ± 7.24 years) were enrolled in the study. The voxel-mirrored homotopic connectivity (VMHC) method was conducted to investigate the different interhemispheric FC between two groups. Then, the seed-based FC method was applied to assess the different FCs with region of interest (ROI) in the brain regions of decreased VMHC between two groups.Results: Compared with HC groups, DR groups showed decreased VMHC values in the bilateral middle temporal gyrus (MTG), lingual/calcarine/middle occipital gyrus (LING/CAL/MOG), superior temporal gyrus (STG), angular (ANG), postcentral gyrus (PosCG), inferior parietal lobule (IPL), and precentral gyrus (PreCG). Meanwhile, altered FC includes the regions of auditory network, visual network, default mode network, salience network, and sensorimotor network. Moreover, a significant positive correlation was observed between the visual acuity-oculus dexter (OD) and zVMHC values in the bilateral LING/CAL/MOG (r = 0.551, p = 0.001), STG (r = 0.426, p = 0.012), PosCG (r = 0.494, p = 0.003), and IPL (r = 0.459, p = 0.006) in DR patients.Conclusion: Our results highlighted that DR patients were associated with substantial impairment of interhemispheric coordination in auditory network, visual network, default mode network, and sensorimotor network. The VMHC might be a promising therapeutic target in the intervention of brain functional dysfunction in DR patients.

scholarly journals Re-Establishing Brain Networks in Patients with ESRD after Successful Kidney Transplantation

2017 ◽  
Vol 13 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Hui Juan Chen ◽  
Jiqiu Wen ◽  
Rongfeng Qi ◽  
Jianhui Zhong ◽  
U. Joseph Schoepf ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Central Executive ◽  
Attention Network ◽  
Default Mode ◽  
Sensorimotor Network ◽  
Dorsal Attention Network ◽  
Visual Network

Background and objectivesCognition in ESRD may be improved by kidney transplantation, but mechanisms are unclear. We explored patterns of resting-state networks with resting-state functional magnetic resonance imaging among patients with ESRD before and after kidney transplantation.Design, setting, participants, & measurementsThirty-seven patients with ESRD scheduled for kidney transplantation and 22 age-, sex-, and education-matched healthy subjects underwent resting-state functional magnetic resonance imaging. Patients were imaged before and 1 and 6 months after kidney transplantation. Functional connectivity of seven resting-state subnetworks was evaluated: default mode network, dorsal attention network, central executive network, self-referential network, sensorimotor network, visual network, and auditory network. Mixed effects models tested associations of ESRD, kidney transplantation, and neuropsychological measurements with functional connectivity.ResultsCompared with controls, pretransplant patients showed abnormal functional connectivity in six subnetworks. Compared with pretransplant patients, increased functional connectivity was observed in the default mode network, the dorsal attention network, the central executive network, the sensorimotor network, the auditory network, and the visual network 1 and 6 months after kidney transplantation (P=0.01). Six months after kidney transplantation, no significant difference in functional connectivity was observed for the dorsal attention network, the central executive network, the auditory network, or the visual network between patients and controls. Default mode network and sensorimotor network remained significantly different from those in controls when assessed 6 months after kidney transplantation. A relationship between functional connectivity and neuropsychological measurements was found in specific brain regions of some brain networks.ConclusionsThe recovery patterns of resting-state subnetworks vary after kidney transplantation. The dorsal attention network, the central executive network, the auditory network, and the visual network recovered to normal levels, whereas the default mode network and the sensorimotor network did not recover completely 6 months after kidney transplantation. Neural resting-state functional connectivity was lower among patients with ESRD compared with control subjects, but it significantly improved with kidney transplantation. Resting-state subnetworks exhibited variable recovery, in some cases to levels that were no longer significantly different from those of normal controls.

Task-positive Functional Connectivity of the Default Mode Network Transcends Task Domain

2015 ◽  
Vol 27 (12) ◽  
pp. 2369-2381 ◽  
Author(s):  
Amanda Elton ◽  
Wei Gao
Keyword(s):  
Functional Connectivity ◽  
Task Performance ◽  
Default Mode Network ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Positive Functional ◽  
Default Mode ◽  
Goal Directed Behavior ◽  
Increased Activity

The default mode network (DMN) was first recognized as a set of brain regions demonstrating consistently greater activity during rest than during a multitude of tasks. Originally, this network was believed to interfere with goal-directed behavior based on its decreased activity during many such tasks. More recently, however, the role of the DMN during goal-directed behavior was established for internally oriented tasks, in which the DMN demonstrated increased activity. However, the well-documented hub position and information-bridging potential of midline DMN regions indicate that there is more to uncover regarding its functional contributions to goal-directed tasks, which may be based on its functional interactions rather than its level of activation. An investigation of task-related changes in DMN functional connectivity during a series of both internal and external tasks would provide the requisite investigation for examining the role of the DMN during goal-directed task performance. In this study, 20 participants underwent fMRI while performing six tasks spanning diverse internal and external domains in addition to a resting-state scan. We hypothesized that the DMN would demonstrate “task-positive” (i.e., positively contributing to task performance) changes in functional connectivity relative to rest regardless of the direction of task-related changes in activity. Indeed, our results demonstrate significant increases in DMN connectivity with task-promoting regions (e.g., anterior insula, inferior frontal gyrus, middle frontal gyrus) across all six tasks. Furthermore, canonical correlation analyses indicated that the observed task-related connectivity changes were significantly associated with individual differences in task performance. Our results indicate that the DMN may not only support a “default” mode but may play a greater role in both internal and external tasks through flexible coupling with task-relevant brain regions.

scholarly journals Maladaptive Self-Focused Attention and Default Mode Network Connectivity: A Transdiagnostic Investigation Across Social Anxiety and Body Dysmorphic Disorders

2021 ◽  
Author(s):  
Angela Fang ◽  
Bengi Baran ◽  
Clare C Beatty ◽  
Jennifer Mosley ◽  
Jamie D Feusner ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Social Anxiety ◽  
Default Mode Network ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Focused Attention ◽  
Neural Basis ◽  
Default Mode ◽  
Body Dysmorphic Disorders ◽  
Primary Body

Abstract Maladaptive self-focused attention (SFA) is a bias toward internal thoughts, feelings, and physical states. Despite its role as a core maintaining factor of symptoms in cognitive theories of social anxiety and body dysmorphic disorders, studies have not examined its neural basis. In this study, we hypothesized that maladaptive SFA would be associated with hyperconnectivity in the default mode network (DMN) in self-focused patients with these disorders. Thirty patients with primary social anxiety disorder or primary body dysmorphic disorder, and 28 healthy individuals were eligible and scanned. Eligibility was determined by scoring greater than 1SD or below 1SD of the Public Self-Consciousness Scale normative mean, respectively, for each group. Seed-to-voxel functional connectivity was computed using a DMN posterior cingulate cortex (PCC) seed. There was no evidence of increased DMN functional connectivity in patients compared to controls. Patients (regardless of diagnosis) showed reduced functional connectivity of the PCC with several brain regions, including the bilateral superior parietal lobule (SPL), compared to controls, which was inversely correlated with maladaptive SFA but not associated with social anxiety, body dysmorphic, or depression severity, or rumination. Abnormal PCC-SPL connectivity may represent a transdiagnostic neural marker of SFA that reflects difficulty shifting between internal versus external attention.

scholarly journals Different resting-state network disruptions in newly diagnosed drug-naïve Parkinson’s disease patients with mild cognitive impairment

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yanbing Hou ◽  
Qianqian Wei ◽  
Ruwei Ou ◽  
Lingyu Zhang ◽  
Xiaoqin Yuan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Independent Component Analysis ◽  
Default Mode Network ◽  
Resting State ◽  
Newly Diagnosed ◽  
Default Mode ◽  
Sensorimotor Network ◽  
Drug Naïve ◽  
Visual Network

Abstract Background Cognitive impairment is a common non-motor symptom in patients with Parkinson’s disease (PD). Mild cognitive impairment (MCI) is also prevalent in nondemented PD patients, even in newly diagnosed PD patients. The possible impacts of MCI on brain function activities for PD patients need more investigation, and the potential of emerging technologies for detecting underlying pathophysiology of cognitive signs in PD can be further improved. Method Forty-seven newly diagnosed drug-naïve PD patients (28 PD-MCI patients and 19 PD patients with cognitively unimpaired (PD-CU)) and 28 healthy controls (HCs) underwent resting-state functional MRI. The connectivity patterns of specific networks were investigated through the independent component analysis among PD-MCI, PD-CU and HCs groups. Results The independent component analysis revealed significantly decreased functional connectivity (FC) of the default mode network, visual network and sensorimotor network in the PD-MCI subgroup compared with the HC group. Furthermore, FC of the default mode network was positively correlated with memory scores from the brief visuospatial memory test-revised, and FC of the visual network was positively correlated with visuospatial scores from the clock copying test in the PD-MCI group. In all patients with PD, FC of the sensorimotor network negatively correlated with motor severity scores from the Unified PD Rating Scale (UPDRS) part III. On the other hand, the potential damage was more likely to occur in FC between the sensorimotor network and limbic network, and between the ventral attention network and visual network in all PD patients. Conclusions Newly diagnosed drug-naïve PD-MCI patients showed characteristic damage of FC within the default mode network, visual network and sensorimotor network, and all PD patients presented impaired FC between the sensorimotor network and limbic network, and FC between the ventral attention network and visual network. These network-wide functional aberrations may underline the pathophysiology of PD.

scholarly journals Altered Spontaneous Neural Activity and Functional Connectivity in Parkinson’s Disease With Subthalamic Microlesion

2021 ◽  
Vol 15 ◽  
Author(s):  
Bei Luo ◽  
Yue Lu ◽  
Chang Qiu ◽  
Wenwen Dong ◽  
Chen Xue ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Functional Connectivity ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Precentral Gyrus

BackgroundTransient improvement in motor symptoms are immediately observed in patients with Parkinson’s disease (PD) after an electrode has been implanted into the subthalamic nucleus (STN) for deep brain stimulation (DBS). This phenomenon is known as the microlesion effect (MLE). However, the underlying mechanisms of MLE is poorly understood.PurposeWe utilized resting state functional MRI (rs-fMRI) to evaluate changes in spontaneous brain activity and networks in PD patients during the microlesion period after DBS.MethodOverall, 37 PD patients and 13 gender- and age-matched healthy controls (HCs) were recruited for this study. Rs-MRI information was collected from PD patients three days before DBS and one day after DBS, whereas the HCs group was scanned once. We utilized the amplitude of low-frequency fluctuation (ALFF) method in order to analyze differences in spontaneous whole-brain activity among all subjects. Furthermore, functional connectivity (FC) was applied to investigate connections between other brain regions and brain areas with significantly different ALFF before and after surgery in PD patients.ResultRelative to the PD-Pre-DBS group, the PD-Post-DBS group had higher ALFF in the right putamen, right inferior frontal gyrus, right precentral gyrus and lower ALFF in right angular gyrus, right precuneus, right posterior cingulate gyrus (PCC), left insula, left middle temporal gyrus (MTG), bilateral middle frontal gyrus and bilateral superior frontal gyrus (dorsolateral). Functional connectivity analysis revealed that these brain regions with significantly different ALFF scores demonstrated abnormal FC, largely in the temporal, prefrontal cortices and default mode network (DMN).ConclusionThe subthalamic microlesion caused by DBS in PD was found to not only improve the activity of the basal ganglia-thalamocortical circuit, but also reduce the activity of the DMN and executive control network (ECN) related brain regions. Results from this study provide new insights into the mechanism of MLE.

scholarly journals Impaired Effective Functional Connectivity of the Sensorimotor Network in Interictal Episodic Migraineurs Without Aura

2020 ◽  
Author(s):  
Heng-Le Wei ◽  
Jing Chen ◽  
Yu-Chen Chen ◽  
Yu-Sheng Yu ◽  
Xi Guo ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Causality Analysis ◽  
Imaging Data ◽  
Sensorimotor Network ◽  
The Right ◽  
The Impact

Abstract Background: Resting-state functional magnetic resonance imaging (Rs-fMRI) has confirmed sensorimotor network (SMN) dysfunction in migraine without aura (MwoA). However, the underlying mechanisms of SMN causal functional connectivity in MwoA remain unclear. We aimed to explore the association between clinical characteristics and effective functional connectivity in SMN, in interictal patients who have MwoA.Methods: We used Rs-fMRI to acquire imaging data in forty episodic patients with MwoA in the interictal phase and thirty-four healthy controls (HCs). Independent component analysis was used to profile the distribution of SMN and calculate the different SMN activity between the two groups. Subsequently, Granger causality analysis was used to analyze the effective causal connectivity between the SMN and other brain regions.Results: Compared to the HCs, MwoA patients showed higher activity in the bilateral postcentral gyri (PoCG) and supplementary motor areas, but lower activity in left Rolandic operculum/insula. Moreover, MwoA patients showed significantly causal connectivity from the SMN to the left calcarine sulcus, left middle temporal gyrus, right angular gyrus and right precuneus. There was also significant causal connectivity from the left calcarine sulcus, left inferior orbitofrontal cortex, right cuneus, right putamen and left inferior parietal lobule to the SMN. In the interictal period, there was positive correlation between the activity of the left PoCG and headache frequency (r = 0.410, p = 0.013), but negative correlation between the activity of the right PoCG and the impact of headache (r = -0.397, p = 0.016). In addition, the disease duration was directly proportional to the connectivity strength from the left PoCG to the right angular gyrus (r = 0.418, p = 0.011), and from the right PoCG to the left calcarine sulcus (r = 0.377, p = 0.023).Conclusions: These differential, resting-state functional activities of the SMN in episodic MwoA may contribute to the understanding of migraine-related intra- and internetwork imbalances associated with nociceptive regulation and chronification.

scholarly journals Modulatory Interactions between the Default Mode Network and Task Positive Networks in Resting-State

2013 ◽  
Author(s):  
Xin Di ◽  
Bharat B. Biswal
Keyword(s):  
Basal Ganglia ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Brain Networks ◽  
Brain Regions ◽  
Salience Network ◽  
Imaging Data ◽  
Default Mode ◽  
Brain Functions

Communications between different brain systems are critical to support complex brain functions. Unlike generally high functional connectivity between brain regions from same system, functional connectivity between regions from different systems are more variable. In the present study, we examined whether the connectivity between different brain networks were modulated by other regions by using physiophysiological interaction (PPI) on resting-state functional magnetic resonance imaging data. Spatial independent component analysis was first conducted to identify the default mode network (DMN) and several task positive networks, including the salience, dorsal attention, left and right executive networks. PPI analysis was conducted between pairs of these networks to identify networks or regions that showed modulatory interactions with the two networks. Network-wise analysis revealed reciprocal modulatory interactions between the DMN, salience, and executive networks. Together with the anatomical properties of the salience network regions, the results suggest that the salience network may modulate the relationship between the DMN and executive networks. In addition, voxel-wise analysis demonstrated that the basal ganglia and thalamus positively interacted with the salience network and the dorsal attention network, and negatively interacted with the salience network and the DMN. The results demonstrated complex relationships among brain networks in resting-state, and suggested that between network communications of these networks may be modulated by some critical brain structures such as the salience network, basal ganglia, and thalamus.

scholarly journals Acute tryptophan loading decreases functional connectivity between the default mode network and emotion‐related brain regions

2018 ◽  
Vol 40 (6) ◽  
pp. 1844-1855 ◽  
Author(s):  
Yacila I. Deza‐Araujo ◽  
Philipp T. Neukam ◽  
Michael Marxen ◽  
Dirk K. Müller ◽  
Thomas Henle ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Brain Regions ◽  
Default Mode

scholarly journals Task-evoked Negative BOLD Response and Functional Connectivity in the Default Mode Network are Representative of Two Overlapping but Separate Neurophysiological Processes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
David B. Parker ◽  
Qolamreza R. Razlighi
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Low Frequency ◽  
Brain Regions ◽  
Intrinsic Activity ◽  
Bold Response ◽  
Default Mode ◽  
Macro Scale ◽  
Negative Bold

Abstract The topography of the default mode network (DMN) can be obtained with one of two different functional magnetic resonance imaging (fMRI) methods: either from the spontaneous but organized synchrony of the low-frequency fluctuations in resting-state fMRI (rs-fMRI), known as “functional connectivity”, or from the consistent and robust deactivations in task-based fMRI (tb-fMRI), here referred to as the “negative BOLD response” (NBR). These two methods are fundamentally different, but their results are often used interchangeably to describe the brain’s resting-state, baseline, or intrinsic activity. While the DMN was initially defined by consistent task-based decreases in blood flow in a set of specific brain regions using PET imaging, recently nearly all studies on the DMN employ functional connectivity in rs-fMRI. In this study, we first show the high level of spatial overlap between NBR and functional connectivity of the DMN extracted from the same tb-fMRI scan; then, we demonstrate that the NBR in putative DMN regions can be significantly altered without causing any change in their overlapping functional connectivity. Furthermore, we present evidence that in the DMN, the NBR is more closely related to task performance than the functional connectivity. We conclude that the NBR and functional connectivity of the DMN reflect two separate but overlapping neurophysiological processes, and thus should be differentiated in studies investigating brain-behavior relationships in both healthy and diseased populations. Our findings further raise the possibility that the macro-scale networks of the human brain might internally exhibit a hierarchical functional architecture.

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