1,720,977 research outputs found
Serotonin 5-HT7 receptor agents: structure-activity relationships and potential therapeutic applications in central nervous system disorders
No full textSince its discovery in the 1940s in serum, the mammalian intestinal mucosa, and in the central nervous
system, serotonin (5-HT) has been shown to be involved in virtually all cognitive and behavioral human
functions, and alterations in its neurochemistry have been implicated in the etiology of a plethora of
neuropsychiatric disorders. The cloning of 5-HT receptor subtypes has been of importance in enabling them to
be classified as specific protein molecules encoded by specific genes. The 5-HT7 receptor is the most recently
classified member of the serotonin receptor family. Since its identification, it has been the subject of intense
research efforts driven by its presence in functionally relevant regions of the brain. The availability of some
selective antagonists and agonists, in combination with genetically modified mice lacking the 5-HT7 receptor,
has allowed for a better understanding of the pathophysiological role of this receptor. This paper reviews data
on localization and pharmacological properties of the 5-HT7 receptor, and summarizes the results of
structure-activity relationship studies aimed at the discovery of selective 5-HT7 receptor ligands. Additionally,
an overview of the potential therapeutic applications of 5-HT7 receptor agonists and antagonists in central
nervous system disorders is presented
RECEPTOR-RECEPTOR INTERACTIONS AN INTEGRATIVE MECHANISM IN NERVE-CELLS
No full textSeveral lines of evidence indicate that interactions among transmission lines can take place at the level of the cell membrane via interactions among macromolecules, integral or associated to the cell membrane, involved in signal recognition and transduction. The present view will focus on this last subject, i.e., on the interactions between receptors for chemical signals at the level of the neuronal membrane (receptor-receptor interaction). By receptor-receptor interaction we mean that a neurotransmitter or modulator, by binding to its receptor, modifies the characteristics of the receptor for another transmitter or modulator. Four types of interactions among transmission Lines may be considered, but mainly intramembrane receptor-receptor interactions have been dealt with in this article, exemplified by the heteroregulation of D2 receptors via neuropeptide receptors and A2 receptors. The role of receptor-receptor interactions in the integration of signals is discussed, especially in terms of filtration of incoming signals, of integration of coincident signals, and of neuronal plasticity
LP-211 is a brain penetrant selective agonist for the serotonin 5-HT7 receptor
No full textWe have determined the pharmacological profile of the new serotonin 5-HT7 receptor agonist N-
(4-cyanophenylmethyl)-4-(2-diphenyl)-1-piperazinehexanamide (LP-211). Radioligand binding assays
were performed on a panel of 5-HT receptor subtypes. The compound was also evaluated in vivo by
examining its effect on body temperature regulation in mice lacking the 5-HT7 receptor (5-HT7−/−) and
their 5-HT7
+/+ sibling controls. Disposition studies were performed in mice of both genotypes. It was found
that LP-211 was brain penetrant and underwent metabolic degradation to 1-(2-diphenyl)piperazine (RA-
7). In vitro binding assays revealed that RA-7 possessed higher 5-HT7 receptor affinity than LP-211 and
a better selectivity profile over a panel of 5-HT receptor subtypes. In vivo it was demonstrated that LP-
211, and to a lesser degree RA-7, induced hypothermia in 5-HT7
+/+ but not in 5-HT7−/− mice. Our results
suggest that LP-211 can be used as a 5-HT7 receptor agonist in vivo
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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