Gray Matter
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Author(s):  
Yuxiang Guo ◽  
Yunxiao Ma ◽  
GongShu Wang ◽  
Ting Li ◽  
Tong Wang ◽  
...  
Keyword(s):  

Author(s):  
Jeremy E. Solly ◽  
Roxanne W. Hook ◽  
Jon E. Grant ◽  
Samuele Cortese ◽  
Samuel R. Chamberlain

AbstractProblematic Usage of the Internet (PUI) has been linked to diverse structural gray matter changes in individual data studies. However, no quantitative synthesis across studies has been conducted. We aimed to identify gray matter regions showing significant spatial convergence across neuroimaging studies in PUI. We searched PubMed and PsycINFO up to 10/03/2021 and included original, cross-sectional comparative studies that examined structural gray matter imaging in PUI versus control groups; reported a whole-brain analysis; and provided peak coordinates for gray matter differences. From a total of 624 potentially relevant studies, 15 (including 355 individuals with PUI and 363 controls) were included in a meta-analysis of voxel-based morphometry studies. Anatomical likelihood estimation (ALE) meta-analysis was performed using extracted coordinates and identified significant spatial convergence in the medial/superior frontal gyri, the left anterior cingulate cortex/cingulate gyrus, and the left middle frontal/precentral gyri. Datasets contributing to these findings all indicated reduced gray matter in cases compared to controls. In conclusion, voxel-based morphometric studies indicate replicable gray matter reductions in the dorsolateral prefrontal cortex and anterior cingulate cortex in PUI, regions implicated in reward processing and top-down inhibitory control. Further studies are required to understand the nature of gray matter differences across PUI behaviors, as well as the contribution of particular mental health disorders, and the influence of variation in study and sample characteristics.


2021 ◽  
Author(s):  
Hua Yu ◽  
Peiyan Ni ◽  
Yang Tian ◽  
Liansheng Zhao ◽  
Mingli Li ◽  
...  

Abstract Objective Inflammation plays a crucial role in the pathogenesis of major depressive disorder (MDD) and bipolar disorder (BD). However, the underlying neurobiological mechanisms are poorly understood. This study aimed to examine whether the dysregulation of complement components contributes to brain structure deficits in BD and MDD patients. Methods A total of 52 BD patients, 35 MDD patients, and 53 mentally healthy controls were recruited from the inpatient and outpatient departments of West China Hospital of Sichuan University. The human complement panel 2-immunology multiplex assay was used to measure the levels of complement C1q, C3, C3b, C4, factor B, factor H, and properdin. Whole brain-based comparison was performed to investigate differences in gray matter volume and cortical thickness among the BD, MDD, and control groups, and relationships were explored between neuroanatomical differences and levels of complement components.Results The gray matter volume in the medial orbital frontal cortex (mOFC) and middle cingulum decreased in both patient groups, while the cortical thickness of the left precentral and left superior frontal gyrus was affected differently. Log10-transformed concentrations of C1q, C4, factor B, factor H, and properdin were higher in both patient groups than in controls, while levels of C1q, factor H, and properdin showed a significant negative correlation with gray matter volume in the mOFC at the voxel-wise level.Conclusion Greater inflammation in mOFC was observed in BD and MDD patients than in controls. Structural deficits in both patient groups were associated with elevated levels of certain complement factors, providing insight into the neuro-inflammatory pathogenesis of mood disorders.


2021 ◽  
Vol 15 ◽  
Author(s):  
Amin Sherafat ◽  
Friederike Pfeiffer ◽  
Akiko Nishiyama

Oligodendrocyte precursor cells (OPCs) are glial cells that differentiate into mature oligodendrocytes (OLs) to generate new myelin sheaths. While OPCs are distributed uniformly throughout the gray and white matter in the developing and adult brain, those in white matter proliferate and differentiate into oligodendrocytes at a greater rate than those in gray matter. There is currently lack of evidence to suggest that OPCs comprise genetically and transcriptionally distinct subtypes. Rather, the emerging view is that they exist in different cell and functional states, depending on their location and age. Contrary to the normal brain, demyelinated lesions in the gray matter of multiple sclerosis brains contain more OPCs and OLs and are remyelinated more robustly than those in white matter. The differences in the dynamic behavior of OL lineage cells are likely to be influenced by their microenvironment. There are regional differences in astrocytes, microglia, the vasculature, and the composition of the extracellular matrix (ECM). We will discuss how the regional differences in these elements surrounding OPCs might shape their phenotypic variability in normal and demyelinated states.


Author(s):  
Cristina Cabrera-Mino ◽  
Bhaswati Roy ◽  
Mary A. Woo ◽  
Matthew J. Freeby ◽  
Rajesh Kumar ◽  
...  

Author(s):  
Xianwen Shang ◽  
Edward Hill ◽  
Zhuoting Zhu ◽  
Jiahao Liu ◽  
B. Zongyuan Ge ◽  
...  

Little is known about whether the association of hypertension with brain volume and dementia is modified by an individual’s age at their diagnosis of hypertension. Our analysis was based on the UK Biobank with baseline data collected between 2006 and 2010. Brain magnetic resonance imaging was used to measure brain volumes between 2014 and 2019. Dementia was ascertained using hospital inpatient, mortality, and self-reported data until 2021. We randomly selected a control participant for each hypertensive participant stratified by hypertension diagnosis age using propensity score. The cohort comprised 11 399 individuals with hypertension and 11 399 controls for the brain volume analysis and 124 053 individuals with hypertension and 124 053 controls for the dementia analysis. Individuals with hypertension diagnosed at ages <35 (β (95% CI, −10.83 [−19.27 to −2.39] mL), 35 to 44 (−6.82 [−12.18 to −1.46] mL), and 45 to 54 years (−3.77 [−6.91 to −0.64] mL) had smaller total brain volume compared with the corresponding controls in the multivariable analysis. Similarly, hypertension diagnosed in early- and mid-life was independently associated with smaller volumes of gray matter, peripheral cortical gray matter, and white matter. Over a median follow-up of 11.9 years, 4626 cases of incident all-cause dementia were documented. Individuals with hypertension diagnosed at 35 to 44 years of age only (hazard ratio [95% CI]: 1.61 [1.31–1.99]) had a higher risk of all-cause dementia compared with the corresponding controls after adjustment for covariates. Hypertension diagnosed in young adulthood or mid-life, but not late life is associated with smaller brain volumes and an increased risk of dementia.


Author(s):  
Ryo Mishima ◽  
Masanori Isobe ◽  
Tomomi Noda ◽  
Keima Tose ◽  
Michiko Kawabata ◽  
...  

Author(s):  
Tine Maria Hansen ◽  
Janusiya Anajan Muthulingam ◽  
Birgitte Brock ◽  
Asbjørn Mohr Drewes ◽  
Anne Juhl ◽  
...  

2021 ◽  
Author(s):  
Xiaosong He ◽  
Lorenzo Caciagli ◽  
Linden M Parkes ◽  
Jennifer Stiso ◽  
Teresa M. Karrer ◽  
...  

The human brain consumes a disproportionate amount of energy to generate neural dynamics. Yet precisely how energetic processes are altered in neurological disorders remains far from understood. Here, we use network control theory to profile the brain's energy landscape, describing the rich dynamical repertoire supported by the structural connectome. This approach allows us to estimate the energy required to activate a circuit, and determine which regions most support that activation. Focusing on temporal lobe epilepsy (TLE), we show that patients require more control energy to activate the limbic network than healthy volunteers, especially ipsilateral to the seizure focus. Further, greater energetic costs are largely localized to the ipsilateral temporo-limbic regions. Importantly, the energetic imbalance between ipsilateral and contralateral temporo-limbic regions is tracked by asymmetric metabolic patterns, which in turn are explained by asymmetric gray matter volume loss. In TLE, failure to meet the extra energy demands may lead to suboptimal brain dynamics and inadequate activation. Broadly, our investigation provides a theoretical framework unifying gray matter integrity, local metabolism, and energetic generation of neural dynamics.


Author(s):  
John W Prineas ◽  
John D E Parratt

Abstract This study examined the roles of microglia and monocytes in myelin destruction in patients with early multiple sclerosis (MS). Twenty-two cases were studied; the clinical duration was &lt;9 weeks in 10 cases. Twenty myeloid cell subtypes or categories were identified including 2 cell types not known previously to occur in demyelinating diseases. Commencing myelin breakdown in plaques and in perivascular and subpial tissues occurred in the immediate presence of infiltrating monocytes and was effected by a homogeneous population of IgG-positive Fc receptor-bearing early phagocytes interacting with abnormal myelin. Oligodendrocyte apoptosis was observed in intact myelinated tissue bordering areas of active demyelination. Capillaries in the cerebral cortex plugged by large numbers of monocytes were common in acute cases of MS and in a patient with a neuromyelitis optica variant and extreme systemic recruitment of monocytes. In an MS patient with progressive disease, microglial nodules centered on MHC-II-positive capillaries plugged by monocytes were present in the cerebral cortex. This constitutes a new gray matter lesion in MS.


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