Replicating Global Brain Connectivity As an Imaging Marker for Depression - Influence of Preprocessing Strategies and Placebo-Controlled Ketamine Treatment

2019 ◽  
Author(s):  
Christoph Kraus ◽  
Anahit Mkrtchian ◽  
Bashkim Kadriu ◽  
Allison C. Nugent ◽  
Carlos A. Zarate Jr. ◽  
...  
Keyword(s):  
Brain Connectivity ◽  
Global Brain

scholarly journals Ketamine Treatment and Global Brain Connectivity in Major Depression

2016 ◽  
Vol 42 (6) ◽  
pp. 1210-1219 ◽  
Author(s):  
Chadi G Abdallah ◽  
Lynnette A Averill ◽  
Katherine A Collins ◽  
Paul Geha ◽  
Jaclyn Schwartz ◽  
...  
Keyword(s):  
Major Depression ◽  
Brain Connectivity ◽  
Global Brain

scholarly journals Threat of shock increases excitability and connectivity of the intraparietal sulcus

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Nicholas L Balderston ◽  
Elizabeth Hale ◽  
Abigail Hsiung ◽  
Salvatore Torrisi ◽  
Tom Holroyd ◽  
...  
Keyword(s):  
Neural Activity ◽  
Brain Connectivity ◽  
Focus Of Attention ◽  
Common Symptom ◽  
Intraparietal Sulcus ◽  
Multimodal Data ◽  
National Health Care ◽  
External Focus ◽  
Internal Focus ◽  
Global Brain

Anxiety disorders affect approximately 1 in 5 (18%) Americans within a given 1 year period, placing a substantial burden on the national health care system. Therefore, there is a critical need to understand the neural mechanisms mediating anxiety symptoms. We used unbiased, multimodal, data-driven, whole-brain measures of neural activity (magnetoencephalography) and connectivity (fMRI) to identify the regions of the brain that contribute most prominently to sustained anxiety. We report that a single brain region, the intraparietal sulcus (IPS), shows both elevated neural activity and global brain connectivity during threat. The IPS plays a key role in attention orienting and may contribute to the hypervigilance that is a common symptom of pathological anxiety. Hyperactivation of this region during elevated state anxiety may account for the paradoxical facilitation of performance on tasks that require an external focus of attention, and impairment of performance on tasks that require an internal focus of attention.

scholarly journals Evaluating global brain connectivity as an imaging marker for depression: influence of preprocessing strategies and placebo-controlled ketamine treatment

2020 ◽  
Vol 45 (6) ◽  
pp. 982-989 ◽  
Author(s):  
Christoph Kraus ◽  
Anahit Mkrtchian ◽  
Bashkim Kadriu ◽  
Allison C. Nugent ◽  
Carlos A. Zarate ◽  
...  
Keyword(s):  
Brain Connectivity ◽  
Global Brain

scholarly journals Fluctuations in Global Brain Activity Are Associated With Changes in Whole-Brain Connectivity of Functional Networks

2016 ◽  
Vol 63 (12) ◽  
pp. 2540-2549 ◽  
Author(s):  
Dustin Scheinost ◽  
Fuyuze Tokoglu ◽  
Xilin Shen ◽  
Emily S. Finn ◽  
Stephanie Noble ◽  
...  
Keyword(s):  
Brain Connectivity ◽  
Brain Activity ◽  
Functional Networks ◽  
Whole Brain ◽  
Global Brain

scholarly journals Ketamine, but Not the NMDAR Antagonist Lanicemine, Increases Prefrontal Global Connectivity in Depressed Patients

2018 ◽  
Vol 2 ◽  
pp. 247054701879610 ◽  
Author(s):  
Chadi G. Abdallah ◽  
Arpan Dutta ◽  
Christopher L. Averill ◽  
Shane McKie ◽  
Teddy J. Akiki ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Brain Connectivity ◽  
Acute Effects ◽  
Major Depressive ◽  
Aspartate Receptor ◽  
Global Signal ◽  
Global Brain ◽  
The Relationship

Background Identifying the neural correlates of ketamine treatment may facilitate and expedite the development of novel, robust, and safe rapid-acting antidepressants. Prefrontal cortex (PFC) global brain connectivity with global signal regression (GBCr) was recently identified as a putative biomarker of major depressive disorder. Accumulating evidence have repeatedly shown reduced PFC GBCr in major depressive disorder, an abnormality that appears to normalize following ketamine treatment. Methods Fifty-six unmedicated participants with major depressive disorder were randomized to intravenous placebo (normal saline; n = 18), ketamine (0.5 mg/kg; n = 19), or lanicemine (100 mg; n = 19). PFC GBCr was computed using time series from functional magnetic resonance imaging scans that were completed at baseline, during infusion, and at 24-h posttreatment. Results Compared to placebo, ketamine significantly increased average PFC GBCr during infusion ( p = 0.01) and at 24-h posttreatment ( p = 0.02). Lanicemine had no significant effects on GBCr during infusion ( p = 0.45) and at 24-h posttreatment ( p = 0.23) compared to placebo. Average delta PFC GBCr (during minus baseline) showed a pattern of positively predicting depression improvement in participants receiving ketamine ( r = 0.44; p = 0.06; d = 1.0) or lanicemine ( r = 0.55; p = 0.01; d = 1.3) but not those receiving placebo ( r = −0.1; p = 0.69; d = 0.02). Follow-up vertex-wise analyses showed ketamine-induced GBCr increases in the dorsolateral, dorsomedial, and frontomedial PFC during infusion and in the dorsolateral and dorsomedial PFC at 24-h posttreatment ( corrected p < 0.05). Exploratory vertex-wise analyses examining the relationship with depression improvement showed positive correlation with GBCr in the dorsal PFC during infusion and at 24-h posttreatment but negative correlation with GBCr in the ventral PFC during infusion ( uncorrected p < 0.01). Conclusions In a randomized placebo-controlled approach, the results provide the first evidence in major depressive disorder of ketamine-induced increases in PFC GBCr during infusion and suggest that ketamine’s rapid-acting antidepressant properties are related to its acute effects on prefrontal connectivity. Overall, the study findings underscore the similarity and differences between ketamine and another N-methyl-D-aspartate receptor antagonist while proposing a pharmacoimaging paradigm for the optimization of novel rapid-acting antidepressants prior to testing in costly clinical trials.

scholarly journals Replicating Global Brain Connectivity as an Imaging Marker for Depression – Influence of Preprocessing Strategies and Randomized Placebo-Controlled Ketamine Treatment

2019 ◽  
Author(s):  
Christoph Kraus ◽  
Anahit Mkrtchian ◽  
Bashkim Kadriu ◽  
Allison C. Nugent ◽  
Carlos A. Zarate ◽  
...  
Keyword(s):  
Antidepressant Treatment ◽  
Brain Connectivity ◽  
Physiological Parameter ◽  
Functional Magnetic Resonance ◽  
Major Depressive ◽  
Global Signal ◽  
Z Scores ◽  
Independent Replication ◽  
Global Brain ◽  
Large Clusters

AbstractMajor depressive disorder (MDD) is associated with altered global brain connectivity (GBC), as assessed via resting state functional magnetic resonance imaging (rsfMRI). Previous studies found that antidepressant treatment with ketamine normalized aberrant GBC changes in the prefrontal and cingulate cortices, warranting further investigations of GBC as a putative imaging marker. However, the results were only obtained via global signal regression (GSR). This study is an independent replication of that analysis using a separate dataset. GBC was analyzed in 28 individuals with MDD and 22 healthy controls (HCs) at baseline, post-placebo, and post-ketamine. To investigate the effects of preprocessing, three distinct pipelines were used: 1) regression of white matter (WM)/cerebrospinal fluid (CSF) signals only (BASE); 2) WM/CSF+GSR (GSR); and 3) WM/CSF+physiological parameter regression (PHYSIO). Compared to PHYSIO and BASE regression, GSR reduced Fisher Z-scores (Fz-scores) in large clusters. PHYSIO did not resemble GBC preprocessed with GSR (GBCr). Reduced GBCr was observed in individuals with MDD at baseline in the anterior and medial cingulate cortices, as well as in the prefrontal cortex. Significant results were only found with GSR. Ketamine had no effect compared to baseline or placebo in either group. These results concur with several studies that used GSR to study GBC. Altered GBCr was observed in the cingulate and prefrontal cortices, but ketamine treatment had no effect. Further investigations are warranted into disease-specific components of global fMRI signals that may drive these results and of GBCr as a potential imaging marker in MDD.

scholarly journals Segregating domain-general from emotional context-specific inhibitory control systems - ventral striatum and orbitofrontal cortex serve as emotion-cognition integration hubs

2020 ◽  
Author(s):  
Qian Zhuang ◽  
Lei Xu ◽  
Feng Zhou ◽  
Shuxia Yao ◽  
Xiaoxiao Zheng ◽  
...  
Keyword(s):  
Inhibitory Control ◽  
Orbitofrontal Cortex ◽  
Ventral Striatum ◽  
Brain Connectivity ◽  
Inferior Frontal Gyrus ◽  
Task Demands ◽  
Emotional Context ◽  
Lower Accuracy ◽  
Context Specific ◽  
Global Brain

AbstractInhibitory control hierarchically regulates cognitive and emotional systems in the service of adaptive goal-directed behavior across changing task demands and environments. While previous studies convergently determined the contribution of prefrontal-striatal systems to general inhibitory control, findings on the specific circuits that mediate the context-specific impact of inhibitory control remained inconclusive. Against this background we employed an evaluated emotional Go/No Go task with fMRI in a large cohort of subjects (N = 250) to segregate brain systems and circuits that mediate domain-general from emotion-specific inhibition control. Particularly during a positive emotional context, behavioral results showed a lower accuracy for No Go trials and a faster response time for Go trials. While the dorsal striatum and lateral frontal regions were involved in inhibitory control irrespective of emotional context, activity in the ventral striatum (VS) and medial orbitofrontal cortex (mOFC) varied as a function of emotional context. On the voxel-wise network level, limbic and striatal systems generally exhibited highest changes in global brain connectivity during inhibitory control, while global brain connectivity of the left mOFC was less suppressed during emotional contexts. Functional connectivity analyses moreover revealed that negative coupling between the VS with inferior frontal gyrus (IFG)/insula and mOFC varied as a function of emotional context. Together these findings indicated separable domain general systems as well emotional context-specific inhibitory brain systems which specifically encompass the VS and its connections with frontal regions.

scholarly journals Multivariate Brain Functional Connectivity Through Regularized Estimators

2020 ◽  
Vol 14 ◽  
Author(s):  
Raymond Salvador ◽  
Norma Verdolini ◽  
Beatriz Garcia-Ruiz ◽  
Esther Jiménez ◽  
Salvador Sarró ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Random Forest ◽  
Temporal Dynamics ◽  
Brain Connectivity ◽  
Brain Activity ◽  
The Other ◽  
Linear Functions ◽  
Other Hand ◽  
Age Related ◽  
Global Brain

Functional connectivity analyses are typically based on matrices containing bivariate measures of covariability, such as correlations. Although this has been a fruitful approach, it may not be the optimal strategy to fully explore the complex associations underlying brain activity. Here, we propose extending connectivity to multivariate functions relating to the temporal dynamics of a region with the rest of the brain. The main technical challenges of such an approach are multidimensionality and its associated risk of overfitting or even the non-uniqueness of model solutions. To minimize these risks, and as an alternative to the more common dimensionality reduction methods, we propose using two regularized multivariate connectivity models. On the one hand, simple linear functions of all brain nodes were fitted with ridge regression. On the other hand, a more flexible approach to avoid linearity and additivity assumptions was implemented through random forest regression. Similarities and differences between both methods and with simple averages of bivariate correlations (i.e., weighted global brain connectivity) were evaluated on a resting state sample of N = 173 healthy subjects. Results revealed distinct connectivity patterns from the two proposed methods, which were especially relevant in the age-related analyses where both ridge and random forest regressions showed significant patterns of age-related disconnection, almost completely absent from the much less sensitive global brain connectivity maps. On the other hand, the greater flexibility provided by the random forest algorithm allowed detecting sex-specific differences. The generic framework of multivariate connectivity implemented here may be easily extended to other types of regularized models.

Alterations in resting‐state global brain connectivity in bipolar I disorder patients with prior suicide attempt

2020 ◽  
Author(s):  
Xiaofang Cheng ◽  
Jianshan Chen ◽  
Xiaofei Zhang ◽  
Yihe Zhang ◽  
Qiuxia Wu ◽  
...  
Keyword(s):  
Suicide Attempt ◽  
Resting State ◽  
Brain Connectivity ◽  
Bipolar I Disorder ◽  
Global Brain

scholarly journals Global brain connectivity alterations in patients with schizophrenia and bipolar spectrum disorders

2016 ◽  
Vol 41 (5) ◽  
pp. 331-341 ◽  
Author(s):  
Kristina C. Skåtun ◽  
Tobias Kaufmann ◽  
Siren Tønnesen ◽  
Guido Biele ◽  
Ingrid Melle ◽  
...  
Keyword(s):  
Brain Connectivity ◽  
Bipolar Spectrum ◽  
Bipolar Spectrum Disorders ◽  
Spectrum Disorders ◽  
Global Brain
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