1,721,001 research outputs found
GLT-1 promoter activity in astrocytes and neurons of mouse hippocampus and somatic sensory cortex
Full text linkGLT-1 eGFP BAC reporter transgenic adult mice were used to detect GLT-1 gene expression in individual cells of CA1, CA3 and SI, and eGFP fl uorescence was measured to analyze quantitatively GLT-1 promoter activity in different cells of neocortex and hippocampus. Virtually all GFAP+ astrocytes were eGFP+; we also found that about 80% of neurons in CA3 pyramidal layer, 10-70% of neurons in I-VI layers of SI and rare neurons in all strata of CA1 and in strata oriens and radiatum of CA3 were eGFP+. Analysis of eGFP intensity showed that astrocytes had a higher GLT-1 promoter activity in SI than in CA1 and CA3, and that neurons had the highest levels of GLT-1 promoter activity in CA3 stratum pyramidale and in layer VI of SI. Finally, we observed that the intensity of GLT-1 promoter activity in neurons is 1-20% of that measured in astrocytes. These results showed that in the hippocampus and neocortex GLT-1 promoter activity is observed in astrocytes and neurons, detailed the distribution of GLT-1 expressing neurons, and indicated that GLT-1 promoter activity in both astrocytes and neurons varies in different brain regions. © 2010 de Vivo, Melone, Rothstein and Conti
Changes in expression of neuronal and glial glutamate transporters in rat hippocampus following kainate-induced seizure activity
No full textEAAC1, a high-affinity glutamate transporter, is localized to astrocytes and GABAergic neurons besides pyramidal cells in rat cerebral cortex.
No full textQuantitative analysis of EAAT4 promoter activity in neurons and astrocytes of mouse somatic sensory cortex
No full textEAAT4-eGFP BAC reporter transgenic adult mice were used to detect EAAT4 gene expression in individual cells of cerebral cortex, and eGFP fluorescence was measured to compare EAAT4 promoter activity in different cells. Most eGFP+ cells were neurons; only rare GFAP+ profiles were eGFP+. About 10% of NeuN+ cells was eGFP+, and the percentage of NeuN/eGFP co-localization varied from 2 to 20% of NeuN+ cells throughout cortical layers: layers I and II-III showed the highest values of co-localization, layer IV the lowest. The intensity of eGFP fluorescence did not exhibit laminar variations. Finally, we observed that EAAT4 promoter activity in cortical neurons was 10% of that measured in cerebellar Purkinje cells, i.e., the cells displaying the highest intensity in the CNS. These results extend our knowledge on EAAT4 expression in the cerebral cortex of adult mice, and suggest that the role of EAAT4 in cortical glutamatergic transmission may be more important than previously thought. © 2010 Elsevier Ireland Ltd
Changes in expression of neuronal and glial glutamate transporters in rat hippocampus following kainate-induced seizure activity
No full text"Purification and characterization of naturally occurring benzodiazepine receptor ligands in rat and human brain."
No full textChemicals that are active at the benzodiazepine receptor (endozepines) are naturally present in the CNS. These substances are present in tissue from humans and animals and in plants and fungi. Using selective extraction protocols, HPLC purification, receptor binding displacement studies, and selective anti-benzodiazepine antibodies, we have identified six or seven peaks of endozepines in rat and human brain. All material could competitively displace [3H]flunitrazepam binding to cerebellar benzodiazepine binding sites. Two peaks also competitively displaced Ro 5-4864 binding to the mitochondrial benzodiazepine binding site. Total amounts of brain endozepines were estimated to be present in potentially physiological concentrations, based on their ability to displace [3H]flunitrazepam binding. Although endozepine peaks 1 and 2 had HPLC retention profiles similar to those of nordiazepam and diazepam, respectively, gas chromatography-mass spectrometry as well as high-performance TLC revealed biologically insignificant amounts of diazepam (less than 0.02 pg/g) and nordiazepam (less than 0.02 pg/g) in the purified material. Electrophysiologically, some purified endozepines positively modulated gamma-aminobutyric acid (GABA) action on Cl- conductance, monitored in patch-clamped cultured cortical neurons or in mammalian cells transfected with cDNA encoding various GABAA receptor subunits. These studies demonstrate that mammalian brains contain endozepines that could serve as potent endogenous positive allosteric modulators of GABAA receptors
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
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
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