1,721,020 research outputs found
Evidence for a presynaptic contribution to the expression of pairing-induced LTP at medial perforant path synapses on dentate granule cells.
No full textAngels and demons: neurotrophic factors and epilepsy
No full textSeveral lines of evidence indicate that neurotrophic factors (NTFs) could be key causal mediators in the development of acquired epileptic syndromes. At the same time, the trophic properties of NTFs suggest that they may be used for the treatment of epilepsy-associated damage. Accordingly, different NTFs, or even the very same NTF, may produce functionally contrasting effects in the context of epilepsy. Recent experimental evidence begins to shed light on the mechanisms underlying these contrasting effects. Understanding these mechanisms will be instrumental for the development of effective therapies that must be based on a careful consideration of the biological properties of NTFs. This review aims at critically evaluating new information emerging in this area and at discussing its implications in the prospect of clinical applications
Basal forebrain neurons suppress amygdala kindling via neocortical but not hippocampal cholinergic projections in rats
No full textAngels and demons: neurotrophic factors and epilepsy.
No full textSeveral lines of evidence indicate that neurotrophic factors (NTFs) could be key causal mediators in the development of acquired epileptic syndromes. Yet the trophic properties of NTFs indicate that they might be used to treat epilepsy-associated damage. Accordingly, different NTFs, or even the same NTF, could produce functionally contrasting effects in the context of epilepsy. Recent experimental evidence begins to shed light on the mechanisms underlying these contrasting effects. Understanding these mechanisms will be instrumental for the development of effective therapies, which must be based on a careful consideration of the biological properties of NTFs. Here, we critically evaluate new information emerging in this area and discuss its implications for clinical treatment
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
Forebrain acetylcholine regulates adult hippocampal neurogenesis and learning
No full textHippocampus-mediated learning enhances neurogenesis in the adult dentate gyrus (DG), and this process has been suggested to be involved in memory formation. The hippocampus receives abundant cholinergic innervation and acetylcholine (ACh) plays an important role in learning and Alzheimer’s disease (AD) pathophysiology. Here, we show that a selective neurotoxic lesion of forebrain cholinergic input with 192 IgG- saporin reduces DG neurogenesis with a concurrent impairment in spatial memory. Conversely, systemic administration of the cholinergic agonist physostigmine increases DG neurogenesis. We find that changes of forebrain ACh levels primarily influence the proliferation and/or the short-term survival rather than the long-term survival or differentiation of the new neurons. We further demonstrate that these newly born cells express the muscarinic receptor subtypes M1 and M4. Our data provide evidence that forebrain ACh promotes neurogenesis, and suggest that the impaired cholinergic function in AD may in part contribute to deficits in learning and memory through reductions in the formation of new hippocampal neurons
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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