scholarly journals Disrupted modular organization of primary sensory brain areas in schizophrenics

2017 ◽  
Author(s):  
Cécile Bordier ◽  
Carlo Nicolini ◽  
Angelo Bifone

AbstractAbnormal brain resting-state functional connectivity has been consistently observed in patients affected by Schizophrenia (SCZ) using functional MRI and other neuroimaging methods. Graph theoretical methods provide a framework to investigate these defective functional interactions and their effects on the modular organization of brain connectivity networks. A few studies have shown abnormal distribution of connectivity within and between functional modules, an indication of imbalanced functional segregation ad integration in SCZ patients. However, no major alterations in the modular structure of functional connectivity networks in patients have been reported, and unambiguous identification of the neural substrates involved remains elusive. Recently, it has been demonstrated that current modularity analysis methods suffer from a fundamental and severe resolution limit, as they fail to detect features that are smaller than a scale determined by the size of the entire connectivity network. This resolution limit is likely to have hampered the ability to resolve differences between patients and controls in previous cross-sectional studies. Here, we apply a novel, resolution limit-free approach to study the modular organization of resting state functional connectivity networks in a large cohort of SCZ patients, and in matched healthy controls. Leveraging these important methodological advances, we find new evidence of substantial fragmentation and reorganization involving primary sensory, auditory and visual areas in SCZ patients. Conversely, frontal and prefrontal areas, typically associated with higher cognitive functions, appear to be largely unaffected, with changes selectively involving language and speech processing areas. Our findings provide support to the hypothesis that cognitive dysfunction in SCZ may arise from deficits occurring already at early stages of sensory processing.

2021 ◽  
Author(s):  
Shervin Assari

While studies have indicated an association between socioeconomic status (SES) and neuroimaging measures, weaker SES effects are shown for Blacks than Whites. This is, in part, due to processes such as stratification, racism, minoritization, and othering of Black people in the United States. However, less is known about Latino youth. This study had two aims: First, to test the association between parental education and the right and left nucleus accumbens (NAcc) resting-state functional connectivity with the frontoparietal network (FPN) in children; and second, to investigate ethnic heterogeneity in this association. This cross-sectional study used data from the Adolescent Brain Cognitive Development (ABCD) study. We analyzed the resting-state functional connectivity data (rsFC) of 10,840 US preadolescents who were between 9 and 10 years old. The main outcomes were the NAcc resting-state functional connectivity with FPN separately calculated for right and left hemispheres. Parental education was our independent variable. Family structure, sex, and age were covariates. Furthermore, ethnicity (Latino vs. non-Latino) was regarded as the moderator. We used mixed-effects regression for data analysis with and without interaction terms between parental education and ethnicity. Most participants (n = 8690; 80.2%) were non-Latino and 2150 (19.8%) were Latino. Parental education was associated with higher right and left NAcc resting-state functional connectivity with FPN. Ethnicity showed statistically significant interactions with parental education, suggesting that the positive associations between parental education and right and left NAcc resting-state functional connectivity with FPN were different in non-Latino and Latino children. For right hemisphere, we found significantly stronger and for left hemisphere, we found significantly weaker association for Latino compared with non-Latino preadolescents. Preadolescents’ NAcc resting-state functional connectivity with FPN depends on the intersections of ethnicity, parental education, and laterality.


2021 ◽  
Author(s):  
Kaley Davis ◽  
Emily Hirsch ◽  
Dylan Gee ◽  
Margaret Andover ◽  
Amy Krain Roy

Abstract Humans are reliant on their caregivers for an extended period of time, offering numerous opportunities for environmental factors, such as parental attitudes and behaviors, to impact brain development. The default mode network is a neural system encompassing the medial prefrontal cortex, posterior cingulate cortex, precuneus, and temporo-parietal junction, which is implicated in aspects of cognition and psychopathology. Delayed default mode network maturation in children and adolescents has been associated with greater general dimensional psychopathology, and positive parenting behaviors have been suggested to serve as protective mechanisms against atypical default mode network development. The current study aimed to extend the existing research by examining whether within- default mode network resting-state functional connectivity would mediate the relation between parental acceptance/warmth and youth psychopathology. Data from the Adolescent Brain and Cognitive Development study, which included a community sample of 9,058 children ages 9-10.9 years, were analyzed to test this prediction. Results from the analysis demonstrated a significant mediation, where greater parental acceptance/warmth predicted greater within- default mode network resting-state functional connectivity, which in turn predicted lower psychopathology. Our study provides preliminary support for the notion that positive parenting traits may reduce the risk for psychopathology in youth through their influence on the default mode network. Due to the cross-sectional nature of this study, we can only draw correlational inference; therefore, these relationships should be tested longitudinally in future investigations.


2018 ◽  
Author(s):  
Omid Kardan ◽  
Mary K. Askren ◽  
Misook Jung ◽  
Scott Peltier ◽  
Bratislav Misic ◽  
...  

AbstractSeveral studies in cancer research have suggested that cognitive dysfunction following chemotherapy, referred to in lay terms as “chemobrain”, is a serious problem. At present, the changes in integrative brain function that underlie such dysfunction remains poorly understood. Recent developments in neuroimaging suggest that patterns of functional connectivity can provide a broadly applicable neuromarker of cognitive performance and other psychometric measures. The current study used multivariate analysis methods to identify patterns of disruption in resting state functional connectivity of the brain due to chemotherapy and the degree to which the disruptions can be linked to behavioral measures of distress and cognitive performance. Sixty two women (22 healthy control, 18 patients treated with adjuvant chemotherapy, and 22 treated without chemotherapy) were evaluated with neurocognitive measures followed by self-report questionnaires and open eyes resting-state fMRI scanning at three time points: diagnosis (M0, pre-adjuvant treatment), at least 1 month (M1), and 7 months (M7) after treatment. The results indicated deficits in cognitive health of breast cancer patients immediately after chemotherapy that improved over time. This psychological trajectory was paralleled by a disruption and later recovery of resting-state functional connectivity, mostly in the parietal and frontal brain regions. The functional connectivity alteration pattern seems to be a separable treatment symptom from the decreased cognitive health. More targeted support for patients should be developed to ameliorate these multi-faceted side effects of chemotherapy treatment on neural functioning and cognitive health.


2020 ◽  
Author(s):  
Ethan T. Whitman ◽  
Siyuan Liu ◽  
Erin Torres ◽  
Allysa Warling ◽  
Kathleen Wilson ◽  
...  

Klinefelter syndrome (47, XXY; Henceforth: XXY syndrome) is a high impact but poorly understood genetic risk factor for neuropsychiatric impairment. Here, we provide the first neuroimaging study to map resting-state functional connectivity (rsFC) changes in XXY syndrome and ask how these might relate to brain anatomy and psychopathology. We collected resting state functional magnetic resonance imaging data from 75 individuals with XXY and 84 healthy XY males. We implemented a brain-wide screen to identify regions with altered global rsFC in XXY vs. XY males, and then used seed-based analysis to decompose these alterations. We further compared rsFC changes with regional changes in brain volume from voxel-based morphometry and tested for correlations between rsFC and symptom variation within XXY syndrome. We found that XXY syndrome was characterized by increased global rsFC in the left dorsolateral prefrontal cortex (DLPFC), associated with overconnectivity with diverse rsFC networks. Regional rsFC changes were partly coupled to regional volumetric changes in XXY syndrome. Within the precuneus, variation in DLPFC rsFC within XXY syndrome was correlated with the severity of psychopathology in XXY individuals. Our findings provide the first view of altered functional brain connectivity in XXY syndrome and delineate links between these alterations and those relating to both brain anatomy and psychopathology. Taken together, these insights advance biological understanding of XXY syndrome as a disorder in its own right, and as a model of genetic risk for psychopathology more broadly.


Neurology ◽  
2019 ◽  
Vol 94 (4) ◽  
pp. e384-e396 ◽  
Author(s):  
Baijayanta Maiti ◽  
Jonathan M. Koller ◽  
Abraham Z. Snyder ◽  
Aaron B. Tanenbaum ◽  
Scott A. Norris ◽  
...  

ObjectiveTo investigate in a cross-sectional study the contributions of altered cerebellar resting-state functional connectivity (FC) to cognitive impairment in Parkinson disease (PD).MethodsWe conducted morphometric and resting-state FC-MRI analyses contrasting 81 participants with PD and 43 age-matched healthy controls using rigorous quality assurance measures. To investigate the relationship of cerebellar FC to cognitive status, we compared participants with PD without cognitive impairment (Clinical Dementia Rating [CDR] scale score 0, n = 47) to participants with PD with impaired cognition (CDR score ≥0.5, n = 34). Comprehensive measures of cognition across the 5 cognitive domains were assessed for behavioral correlations.ResultsThe participants with PD had significantly weaker FC between the vermis and peristriate visual association cortex compared to controls, and the strength of this FC correlated with visuospatial function and global cognition. In contrast, weaker FC between the vermis and dorsolateral prefrontal cortex was found in the cognitively impaired PD group compared to participants with PD without cognitive impairment. This effect correlated with deficits in attention, executive functions, and global cognition. No group differences in cerebellar lobular volumes or regional cortical thickness of the significant cortical clusters were observed.ConclusionThese results demonstrate a correlation between cerebellar vermal FC and cognitive impairment in PD. The absence of significant atrophy in cerebellum or relevant cortical areas suggests that this could be related to local pathophysiology such as neurotransmitter dysfunction.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi281-vi281
Author(s):  
Walter Block ◽  
Rasmus Birns ◽  
Miles Olsen ◽  
Samuel Hurley ◽  
Ethan Brodsky ◽  
...  

Abstract INTRODUCTION The spatial and temporal resolution limits of functional MRI (fMRI) brain mapping provide primarily correlative information on brain connectivity. Determining how one region causally modulates and mediates activity in other regions remains difficult with fMRI. We demonstrate a simple means to add causality in resting state functional connectivity MRI (rs-fcMRI) using techniques developed first for convection-enhanced delivery (CED) of therapeutics. Here we use CED to guide and monitor pharmacologic alteration of a local brain region in anaesthetized Rhesus monkeys while monitoring rs-fcMRI signal changes. METHODS Pre-surgical MRI was used to determine skull locations for craniotomies for installation of NavigusTMbrain ports in two untrained monkeys slated for euthanasia. The ports were aligned in real–time to provide trajectories aimed at the central nucleus of the amygdala (CeA). Fused silica catheters were then inserted into the CeA where 24 mg of muscimol (inhibitory agent) was infused in 24 ml of buffered solution under pressure over 12 minutes, first on the right side and then on the left side. rs-fcMRI studies were done for 45 minutes before and after the unilateral infusion and then after the bilateral infusion. RESULTS Catheters were successfully aligned and inserted into the CeA targets with sub-mm accuracy. T2-weighted imaging detected the enhanced T2 from the infusion’s buffer. Pre-infusion rs-fcMRI provides results consistent with prior studies, which have shown that the CeA is most strongly connected to the contralateral CeA. This connectivity was significantly reduced following both unilateral and bilateral injections of muscimol into the CeA, demonstrating the effectiveness of the muscimol infusions. Conditional Grainger Causality (CGC) analysis shows unexpected new connectivity after the unilateral infusion. Upon the bilateral infusion, global effective connectivity in the region is reduced. CONCLUSION Expected and unexpected changes in resting state functional connectivity resulted from unilateral and bilateral infusions of inhibitory agents.


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