1,720,980 research outputs found
The selective glucocorticoid receptor antagonist ORG 34116 decreases immobility time in the forced swim test and affects cAMP-responsive element-binding protein phosphorylation in rat brain
No full textGlucocorticoid receptor (GR) antagonists can block the retention of the immobility response in the forced swimming test. Recently, we showed that forced swimming evokes a distinct spatiotemporal pattern of cAMP-responsive element-binding protein (CREB) phosphorylation in the dentate gyrus (DG) and neocortex. In the present study, we found that chronic treatment of rats with the selective GR antagonist ORG 34116 decreased the immobility time in the forced swim test, increased baseline levels of phosphorylated CREB (P-CREB) in the DG and neocortex and affected the forced swimming-induced changes in P-CREB levels in a time- and site-specific manner. Overall, we observed that, in control rats, forced swimming evoked increases in P-CREB levels in the DG and neocortex, whereas in ORG 34116-treated animals a major dephosphorylation of P-CREB was observed. These observations underscore an important role of GRs in the control of the phosphorylation state of CREB which seems to be of significance for the immobility response in the forced swim test and extend the molecular mechanism of action of GRs in the brain.</p
Interactions between corticotropin-releasing hormone and serotonin: implications for the aetiology and treatment of anxiety disorders
No full text
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
Stress and the brain: Solving the puzzle using microdialysis
No full textAberrant functioning of the hypothalamic–pituitary–adrenocortical (HPA) axis seems to be involved in depression and anxiety. However, the mechanisms underlying the relationship between stress and mental illness are not completely resolved yet. The therapeutical efficacy of selective serotonin re-uptake inhibitors and benzodiazepines points to a key role of serotonin and gamma-aminobutyric acid (GABA) in depression and anxiety. Thus, it can be hypothesised that stress-induced changes in serotonin and GABA contribute to a dysregulation of the HPA axis and to the development of psychiatric disorders in susceptible subjects. It will, therefore, be crucial to increase our understanding of the effects of stress on serotonin and GABA. Various refinements have made in vivo microdialysis an extremely powerful method to study the highly dynamic neurotransmitter responses in stress physiology and behaviour. Furthermore, microdialysis can also be used to measure free corticosterone levels in the previous termbrainnext term and, thus, HPA axis activity and neurotransmission can be monitored concomitantly. Here we review the effects of acute and chronic stress on serotonin and GABA, as assessed by microdialysis, in the hippocampus; a previous termbrainnext term structure critically involved in the behavioural and neuroendocrine responses to stress. From the microdialysis data discussed, it can be concluded that both serotonin and GABA in the hippocampus are highly responsive to stress, but also that these responses are shaped by the exact nature of the stressor, i.e. the balance between the psychological and physical aspects of the stressful challenge.Aberrant functioning of the hypothalamic–pituitary–adrenocortical (HPA) axis seems to be involved in depression and anxiety. However, the mechanisms underlying the relationship between stress and mental illness are not completely resolved yet. The therapeutical efficacy of selective serotonin re-uptake inhibitors and benzodiazepines points to a key role of serotonin and gamma-aminobutyric acid (GABA) in depression and anxiety. Thus, it can be hypothesised that stress-induced changes in serotonin and GABA contribute to a dysregulation of the HPA axis and to the development of psychiatric disorders in susceptible subjects. It will, therefore, be crucial to increase our understanding of the effects of stress on serotonin and GABA. Various refinements have made in vivo microdialysis an extremely powerful method to study the highly dynamic neurotransmitter responses in stress physiology and behaviour. Furthermore, microdialysis can also be used to measure free corticosterone levels in the previous termbrainnext term and, thus, HPA axis activity and neurotransmission can be monitored concomitantly. Here we review the effects of acute and chronic stress on serotonin and GABA, as assessed by microdialysis, in the hippocampus; a previous termbrainnext term structure critically involved in the behavioural and neuroendocrine responses to stress. From the microdialysis data discussed, it can be concluded that both serotonin and GABA in the hippocampus are highly responsive to stress, but also that these responses are shaped by the exact nature of the stressor, i.e. the balance between the psychological and physical aspects of the stressful challenge
- …
