1,720,990 research outputs found
Microglial cells: Sensors for neuronal activity and microbiota-derived molecules
No full textMicroglial cells play pleiotropic homeostatic activities in the brain, during development and in adulthood. Microglia regulate synaptic activity and maturation, and continuously patrol brain parenchyma monitoring for and reacting to eventual alterations or damages. In the last two decades microglia were given a central role as an indicator to monitor the inflammatory state of brain parenchyma. However, the recent introduction of single cell scRNA analyses in several studies on the functional role of microglia, revealed a not-negligible spatio-temporal heterogeneity of microglial cell populations in the brain, both during healthy and in pathological conditions. Furthermore, the recent advances in the knowledge of the mechanisms involved in the modulation of cerebral activity induced by gut microbe-derived molecules open new perspectives for deciphering the role of microglial cells as possible mediators of these interactions. The aim of this review is to summarize the most recent studies correlating gut-derived molecules and vagal stimulation, as well as dysbiotic events, to alteration of brain functioning, and the contribution of microglial cells
Metabolic dynamics in astrocytes and microglia during post-natal development and their implications for autism spectrum disorders
No full textAutism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by elusive underlying mechanisms. Recent attention has focused on the involvement of astrocytes and microglia in ASD pathology. These glial cells play pivotal roles in maintaining neuronal homeostasis, including the regulation of metabolism. Emerging evidence suggests a potential association between ASD and inborn errors of metabolism. Therefore, gaining a comprehensive understanding of the functions of microglia and astrocytes in ASD is crucial for the development of effective therapeutic interventions. This review aims to provide a summary of the metabolism of astrocytes and microglia during post-natal development and the evidence of disrupted metabolic pathways in ASD, with particular emphasis on those potentially important for the regulation of neuronal post-natal maturation by astrocytes and microglia
Functional roles of the Ca2+-activated K+ channel, KCa3.1, in brain tumors
No full textGlioblastoma is the most aggressive and deadly brain tumor, with low disease-free period even after surgery and combined radio and chemotherapies. Among the factors contributing to rapid tumor growth in the brain are the elevated proliferation and invasion rate, and the ability to induce a local immunosuppressive environment. The intermediate-conductance Ca2+-activated K+ channel KCa3.1 is expressed on glioblastoma cells and in tumor-infiltrating cells. In tumor cells, the functional expression of KCa3.1 is important to modulate cell invasion and proliferation. In tumor infiltrating cells KCa3.1 activity is required to regulate their activation state. Interfering with KCa3.1 activity can be an adjuvant therapeutic approach in addition to classic chemotherapy, to counteract tumor growth and prolong patient's survival. In this mini-review we discuss the evidence of the functional roles of KCa3.1 channels in glioblastoma biolog
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Adaptation to G93A superoxide dismutase 1 in a motor neuron cell line model of amyotrophic lateral sclerosis. The role of glutathione
Full text linkMotor neuron degeneration in amyotrophic lateral sclerosis involves oxidative
damage. Glutathione (GSH) is critical as an antioxidant and a redox
modulator. We used a motor neuronal cell line (NSC-34) to investigate
whether wild-type and familial amyotrophic lateral sclerosis-linked G93A
mutant Cu,Zn superoxide dismutase (wt ⁄G93ASOD1) modified the GSH
pool and glutamate cysteine ligase (GCL), the rate-limiting enzyme for
GSH synthesis. We studied the effect of various G93ASOD1 levels and
exposure times. Mutant Cu,Zn superoxide dismutase induced an adaptive
process involving the upregulation of GSH synthesis, even at very low
expression levels. However, cells with a high level of G93ASOD1 cultured
for 10 weeks showed GSH depletion and a decrease in expression of the
modulatory subunit of GCL. These cells also had lower levels of GSH and
GCL activity was not induced after treatment with the pro-oxidant tertbutylhydroquinone.
Cells with a low level of G93ASOD1 maintained
higher GSH levels and GCL activity, showing that the exposure time and
the level of the mutant protein modulate GSH synthesis. We conclude that
failure of the regulation of the GSH pathway caused by G93ASOD1 may
contribute to motor neuron vulnerability and we identify this pathway as a
target for therapeutic intervention
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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