scholarly journals Widespread Decrease of Cerebral Vimentin-Immunoreactive Astrocytes in Depressed Suicides

2021 ◽  
Vol 12 ◽  
Author(s):  
Liam Anuj O'Leary ◽  
Claudia Belliveau ◽  
Maria Antonietta Davoli ◽  
Jie Christopher Ma ◽  
Arnaud Tanti ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Blood Vessels ◽  
Close Association ◽  
Brain Regions ◽  
Quantitative Comparison ◽  
Post Mortem ◽  
Dorsomedial Prefrontal Cortex ◽  
Post Mortem Brain ◽  
Morphometric Features ◽  
Fine Morphology

Post-mortem investigations have implicated cerebral astrocytes immunoreactive (-IR) for glial fibrillary acidic protein (GFAP) in the etiopathology of depression and suicide. However, it remains unclear whether astrocytic subpopulations IR for other astrocytic markers are similarly affected. Astrocytes IR to vimentin (VIM) display different regional densities than GFAP-IR astrocytes in the healthy brain, and so may be differently altered in depression and suicide. To investigate this, we compared the densities of GFAP-IR astrocytes and VIM-IR astrocytes in post-mortem brain samples from depressed suicides and matched non-psychiatric controls in three brain regions (dorsomedial prefrontal cortex, dorsal caudate nucleus and mediodorsal thalamus). A quantitative comparison of the fine morphology of VIM-IR astrocytes was also performed in the same regions and subjects. Finally, given the close association between astrocytes and blood vessels, we also assessed densities of CD31-IR blood vessels. Like for GFAP-IR astrocytes, VIM-IR astrocyte densities were found to be globally reduced in depressed suicides relative to controls. By contrast, CD31-IR blood vessel density and VIM-IR astrocyte morphometric features in these regions were similar between groups, except in prefrontal white matter, in which vascularization was increased and astrocytes displayed fewer primary processes. By revealing a widespread reduction of cerebral VIM-IR astrocytes in cases vs. controls, these findings further implicate astrocytic dysfunctions in depression and suicide.

scholarly journals Widespread decrease of cerebral vimentin-immunoreactive astrocytes in depressed suicides

2020 ◽  
Author(s):  
Liam Anuj O’Leary ◽  
Claudia Belliveau ◽  
Maria Antonietta Davoli ◽  
Jie Christopher Ma ◽  
Arnaud Tanti ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
White Matter ◽  
Blood Vessels ◽  
Close Association ◽  
Brain Regions ◽  
Quantitative Comparison ◽  
Postmortem Brain ◽  
Dorsomedial Prefrontal Cortex ◽  
Morphometric Features ◽  
Fine Morphology

1AbstractPostmortem investigations have implicated cerebral astrocytes immunoreactive (-IR) for glial fibrillary acidic protein (GFAP) in the etiopathology of depression and suicide. However, it remains unclear whether astrocytic subpopulations IR for other astrocytic markers are similarly affected. Astrocytes IR to vimentin (VIM) display different regional densities than GFAP-IR astrocytes in the healthy brain, and so may be differently altered in depression and suicide. To investigate this, we compared the densities of GFAP-IR astrocytes and VIM-IR astrocytes in postmortem brain samples from depressed suicides and matched non-psychiatric controls in three brain regions (dorsomedial prefrontal cortex, dorsal caudate nucleus and mediodorsal thalamus). A quantitative comparison of the fine morphology of VIM-IR astrocytes was also performed in the same regions and subjects. Finally, given the close association between astrocytes and blood vessels, we also assessed densities of CD31-IR blood vessels. Like for GFAP-IR astrocytes, VIM-IR astrocyte densities were found to be globally reduced in depressed suicide relative to controls. By contrast, CD31-IR blood vessel density and VIM-IR astrocyte morphometric features in these regions were similar between groups, except in prefrontal white matter, in which vascularization was increased and astrocytes displayed fewer primary processes. By revealing a widespread reduction of cerebral VIM-IR astrocytes in cases vs. controls, these findings further implicate astrocytic dysfunctions in depression and suicide.

scholarly journals Characterizing the Theory of Mind Network in Schizophrenia Reveals a Sparser Network Structure

2020 ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Arne Nagels ◽  
Irina Falkenberg ◽  
Benjamin Straube
Keyword(s):  
Prefrontal Cortex ◽  
Social Functioning ◽  
Network Structure ◽  
Functional Integration ◽  
Signs And Symptoms ◽  
Brain Regions ◽  
Interpersonal Behavior ◽  
Single Subject ◽  
Dorsomedial Prefrontal Cortex ◽  
The Right

AbstractImpaired social functioning is a hallmark of schizophrenia and altered functional integration between distant brain regions are expected to account for signs and symptoms of the disorder. The functional neuroarchitecture of a network relevant for social functioning, the mentalizing network, is however poorly understood. In this study we examined dysfunctions of the mentalizing network in patients with schizophrenia compared to healthy controls via dynamic causal modelling and an interactive social decision-making game. Network characteristics were analyzed on a single subject basis whereas graph theoretic metrics such as in-degree, out-degree and edge-connectivity per network node were compared between the groups. The results point to a sparser network structure in patients with schizophrenia and highlight the dorsomedial prefrontal cortex as a disconnected network hub receiving significantly less input from other brain regions in the network. Further analyses suggest that integrating pathways from the right and the left temporo-parietal junction into the dorsomedial prefrontal cortex were less frequently found in patients with schizophrenia. Brain and behavior analyses further suggest that the connectivity-intactness within the entire network is associated with functional interpersonal behavior during the task. Thus, the neurobiological alterations within the mentalizing network in patients with schizophrenia point to a specific integration deficit between core brain regions underlying the generation of higher-order representations and thereby provide a potential treatment target.

scholarly journals Platelet phosphorylated TDP-43: An exploratory study for a peripheral surrogate biomarker development for Alzheimer’s disease

2017 ◽  
Author(s):  
Rodger Wilhite ◽  
Jessica Sage ◽  
Abdurrahman Bouzid ◽  
Tyler Primavera ◽  
Abdulbaki Agbas
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Stage ◽  
Clinical Signs ◽  
Brain Regions ◽  
Post Mortem ◽  
Disease Prognosis ◽  
Post Mortem Brain ◽  
And Control ◽  
Lateral Sclerosis

AbstractAim: Alzheimer’s disease (AD) and other forms of dementia create a non-curable disease population in World’s societies. To develop a blood-based biomarker is important so that the remedial or disease-altering therapeutic intervention for AD patients would be available at the early stage. Materials & Methods: TDP-43 levels were analyzed in post-mortem brain tissue and platelets of AD and control subjects. Results: We observed an increased TDP-43 (<60%) in post-mortem AD brain regions and similar trends were also observed in patient’s platelets. Conclusion: Platelet TDP-43 could be used as a surrogate biomarker that is measurable, reproducible, and sensitive for screening the patients with some early clinical signs of AD and can be used to monitor disease prognosis.Lay abstractIn this study, we explore to identify an Alzheimer’s disease-selective phospho-specific antibody that recognizes the diseased form of TDP-43 protein in patient’s blood-derived platelets. Our results suggest that selective anti-phosphorylated TDP-43 antibody discriminates Alzheimer’s disease from non-demented controls and patients with amyotrophic lateral sclerosis. Therefore, platelet screening with a selective antibody could potentially be a useful tool for diagnostic purposes for Alzheimer’s disease.

scholarly journals Dorsolateral and dorsomedial prefrontal cortex track distinct properties of dynamic social behavior

2020 ◽  
Vol 15 (4) ◽  
pp. 383-393
Author(s):  
Kelsey R McDonald ◽  
John M Pearson ◽  
Scott A Huettel
Keyword(s):  
Prefrontal Cortex ◽  
Video Game ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Strategic Action ◽  
General Role ◽  
Temporoparietal Junction ◽  
Dorsomedial Prefrontal Cortex ◽  
Decision Neuroscience ◽  
Dorsolateral Prefrontal

Abstract Understanding how humans make competitive decisions in complex environments is a key goal of decision neuroscience. Typical experimental paradigms constrain behavioral complexity (e.g. choices in discrete-play games), and thus, the underlying neural mechanisms of dynamic social interactions remain incompletely understood. Here, we collected fMRI data while humans played a competitive real-time video game against both human and computer opponents, and then, we used Bayesian non-parametric methods to link behavior to neural mechanisms. Two key cognitive processes characterized behavior in our task: (i) the coupling of one’s actions to another’s actions (i.e. opponent sensitivity) and (ii) the advantageous timing of a given strategic action. We found that the dorsolateral prefrontal cortex displayed selective activation when the subject’s actions were highly sensitive to the opponent’s actions, whereas activation in the dorsomedial prefrontal cortex increased proportionally to the advantageous timing of actions to defeat one’s opponent. Moreover, the temporoparietal junction tracked both of these behavioral quantities as well as opponent social identity, indicating a more general role in monitoring other social agents. These results suggest that brain regions that are frequently implicated in social cognition and value-based decision-making also contribute to the strategic tracking of the value of social actions in dynamic, multi-agent contexts.

scholarly journals Variable telomere length across post-mortem human brain regions and specific reduction in the hippocampus of major depressive disorder

2015 ◽  
Vol 5 (9) ◽  
pp. e636-e636 ◽  
Author(s):  
F Mamdani ◽  
B Rollins ◽  
L Morgan ◽  
R M Myers ◽  
J D Barchas ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Prefrontal Cortex ◽  
Depressive Disorder ◽  
Telomere Length ◽  
Dorsolateral Prefrontal Cortex ◽  
Brain Regions ◽  
Cellular Aging ◽  
Post Mortem ◽  
Major Depressive ◽  
Dorsolateral Prefrontal

Abstract Stress can be a predisposing factor to psychiatric disorders and has been associated with decreased neurogenesis and reduced hippocampal volume especially in depression. Similarly, in white blood cells chronic psychological stress has been associated with telomere shortening and with mood disorders and schizophrenia (SZ). However, in previous post-mortem brain studies from occipital cortex and cerebellum, no difference in telomere length was observed in depression. We hypothesized that in psychiatric disorders, stress-driven accelerated cellular aging can be observed in brain regions particularly sensitive to stress. Telomere length was measured by quantitative-PCR in five brain regions (dorsolateral prefrontal cortex, hippocampus (HIPP), amygdala, nucleus accumbens and substantia nigra (SN)) in major depressive disorder (MDD), bipolar disorder, SZ and normal control subjects (N=40, 10 subjects per group). We observed significant differences in telomere length across brain regions suggesting variable levels of cell aging, with SN and HIPP having the longest telomeres and the dorsolateral prefrontal cortex the shortest. A significant decrease (P<0.02) in telomere length was observed specifically in the HIPP of MDD subjects even after controlling for age. In the HIPP of MDD subjects, several genes involved in neuroprotection and in stress response (FKBP5, CRH) showed altered levels of mRNA. Our results suggest the presence of hippocampal stress-mediated accelerated cellular aging in depression. Further studies are needed to investigate the cellular specificity of these findings.

scholarly journals Altered expression of a unique set of genes reveals complex etiology of Schizophrenia

2017 ◽  
Author(s):  
Ashutosh Kumar ◽  
Himanshu Narayan Singh ◽  
Vikas Pareek ◽  
Khursheed Raza ◽  
Pavan Kumar ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Mrna Expression ◽  
Brain Regions ◽  
Contributing Factors ◽  
Altered Expression ◽  
Expression Of Genes ◽  
Affy Package ◽  
Post Mortem Brain ◽  
A Genome ◽  
Neuronal Functions

AbstractPurposeThe etiology of schizophrenia is extensively debated, and multiple factors have been contended to be involved. A panoramic view of the contributing factors in a genome-wide study can be an effective strategy to provide a comprehensive understanding of its causality.Materials and MethodsGSE53987 dataset downloaded from GEO-database, which comprised mRNA expression data of post-mortem brain tissue across three regions from control and age-matched subjects of schizophrenia (N= Hippocampus (HIP): C-15, T-18, Prefrontal cortex (PFC): C-15, T-19, Associative striatum (STR): C-18, T-18). Bio-conductor-affy-package used to compute mRNA expression, and further t-test applied to investigate differential gene expression. The analysis of the derived genes performed using PANTHER Classification System and NCBI database.ResultsA set of 40 genes showed significantly altered (p<0.01) expression across all three brain regions. The analyses unraveled genes implicated in biological processes and events, and molecular pathways relating basic neuronal functions.ConclusionsThe deviant expression of genes maintaining basic cell machinery explains compromised neuronal processing in SCZ.AbbreviationsSchizophrenia (SCZ), Hippocampus (HIP), Associative striatum (STR), Prefrontal cortex (PFC)

scholarly journals Single-cell deconvolution of 3,000 post-mortem brain samples for eQTL and GWAS dissection in mental disorders

2021 ◽  
Author(s):  
Yongjin Park ◽  
Liang He ◽  
Jose Davila-Velderrain ◽  
Lei Hou ◽  
Shahin Mohammadi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Genetic Variants ◽  
Cell Types ◽  
Brain Regions ◽  
Post Mortem ◽  
Rna Seq ◽  
Cell Type ◽  
Post Mortem Brain ◽  
Cell Type Specific

AbstractThousands of genetic variants acting in multiple cell types underlie complex disorders, yet most gene expression studies profile only bulk tissues, making it hard to resolve where genetic and non-genetic contributors act. This is particularly important for psychiatric and neurodegenerative disorders that impact multiple brain cell types with highly-distinct gene expression patterns and proportions. To address this challenge, we develop a new framework, SPLITR, that integrates single-nucleus and bulk RNA-seq data, enabling phenotype-aware deconvolution and correcting for systematic discrepancies between bulk and single-cell data. We deconvolved 3,387 post-mortem brain samples across 1,127 individuals and in multiple brain regions. We find that cell proportion varies across brain regions, individuals, disease status, and genotype, including genetic variants in TMEM106B that impact inhibitory neuron fraction and 4,757 cell-type-specific eQTLs. Our results demonstrate the power of jointly analyzing bulk and single-cell RNA-seq to provide insights into cell-type-specific mechanisms for complex brain disorders.

Neurochemical differences in two rat strains exposed to social isolation rearing

2012 ◽  
Vol 24 (5) ◽  
pp. 286-295 ◽  
Author(s):  
Luigia Trabace ◽  
Margherita Zotti ◽  
Marilena Colaianna ◽  
Maria G. Morgese ◽  
Stefania Schiavone ◽  
...  
Keyword(s):  
High Performance ◽  
Tissue Concentration ◽  
Brain Area ◽  
Brain Regions ◽  
Post Mortem ◽  
Isolation Rearing ◽  
Post Mortem Brain ◽  
Rat Strain ◽  
Neurochemical Changes

Objective: Isolation rearing of rats provides a non-pharmacological method of inducing behavioural changes in rodents that resemble schizophrenia or depression. Nevertheless, results are variable within different strains. We focused on neurochemical changes in several in vivo and post-mortem brain regions of Wistar (W) and Lister Hooded (LH) rats following post-weaning social separation.Methods: Experiments were conducted after 6–8 weeks of isolation. For post-mortem studies, prefrontal cortex (PFC), nucleus accumbens (NAC), hippocampus (Hipp) and striatum (St) were collected by tissue dissection. In vivo experiments were conducted by microdialysis in the PFC. Analyses of dopamine (DA), serotonin (5-HT) levels and relative turnover were performed by using high-performance liquid chromatography.Results: We found significant strain-related differences in biogenic amine content. LH rats were characterised by markedly raised DA, along with its turnover reduction, in all the post-mortem brain regions examined as well as in microdialysis samples, while in W rats 5-HT tissue concentration was lower in PFC and St and higher in NAC and Hipp. Cortical extracellular 5-HT concentrations were increased in group housed and decreased in isolated W animals. Moreover, isolation increased DA concentrations in the PFC of LH rats, and decreased 5-HT in W rats in NAC and Hipp. Lately, 5-HT turnover was also affected by both strain and isolation conditions.Conclusions: This study suggests that W and LH rats have markedly different neurochemical profiles in response to isolation, resulting in altered monoamine levels that vary according to brain area and rat strain. These findings highlight the importance of selecting an appropriate rat strain when considering isolation rearing to model symptoms of schizophrenia and/or depression.

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