1,720,957 research outputs found
The effect of maternal and postnatal obesity on offspring anxiety and memory and the role of altered HPA axis function and neuroinflammation
No full textPoor maternal nutrition during pregnancy is detrimental to fetal development and adversely affects long-term health by increasing the risk of chronic diseases, such as neuropsychiatric disorders. Previous studies show that maternal obesity may influence offspring behaviour such as anxiety/stress in adult life. This may be due to altered development of the hypothalamo-pituitaryadrenal (HPA) axis. This may be exacerbated by obesity in adult life which independently influences behaviour and HPA axis function. The mechanisms behind the effect of obesity to impact neuropsychiatric disorders is unclear, however increased inflammation found in obese individuals may be inducing permanent changes to HPA function. This study investigated the effects of maternal and postnatal obesity on behaviour, HPA axis function in young and mature adult mouse offspring, and assessed neuroinflammation as a potential mechanism. In this study, female C57BL/6 mice were fed either an obesogenic high-fat diet (HF; 45% kcal fat) or control diet (C; 7% kcal fat) 6 weeks before mating, throughout pregnancy and lactation. Offspring were fed C or HF diet from weaning onwards. Maternal care and pup anxiety were assessed on postnatal day 7 via pup retrieval and ultrasonic vocalisations (USVs) during maternal separation. In 15 and 52 week-old offspring, anxiety was assessed by open field (OF) and elevated plus maze (EPM) and memory was assessed by novel object recognition (NOR). Corticosterone and ACTH concentrations (basal and area under curve [AUC]) were measured during a 30 minute restraint test. Analysis of neuroinflammation was performed via immunohistochemistry and mRNA levels of genes associated with HPA axis function and inflammation. A maternal obesogenic HF diet was associated with poor maternal care and anxiety in males from 1 week of age, and subtle changes to anxiety persisted into young and mature adulthood. Postnatal obesity was associated with decreased and increased anxiety at 15 and 52 weeks of age respectively, and memory was impaired at 15 but not 52 weeks of age in males. Changes in anxiety and memory were associated with HPA dysregulation and microglial activation in the brain at 15 but not 52 weeks of age in males. In female offspring, changes in anxiety and memory were only observed at 52 weeks of age due to postnatal and maternal obesity respectively. Anxiety, but not memory, in females corresponded to changes in HPA regulation, but not inflammation at this age. Maternal obesity, in addition to further postnatal obesity, subtly exacerbates some effects of anxiety and the stress response which is seen primarily in male, but not female, offspring at multiple ages. Overall, the effect of maternal obesity is sex-specific and age-dependent. These data are a novel addition to the existing literature on the effects of maternal obesity on HPA axis function and behaviour, particularly due to the additional assessment of further postnatal obesity. Further analysis of the role of inflammation during obesity at different stages of the life course will enhance our understanding of the risk of neuropsychiatric disorders to future generations.<br/
Maternal and postweaning obesity alters regulation of the hypothalamo-pituitary adrenal axis in mature adult mice
No full textBackground/Aims: Obesity is a major risk factor for non-communicable diseases, including psychiatric disorders such as anxiety. This may be due to altered hypothalamo-pituitary adrenal function. However, we showed previously that anxiety in young adult life was not affected by a maternal or post-weaning obesogenic high fat (HF) diet. Here we examined the effect of these HF diets on anxiety in mature adult life and related it to adrenal morphology.
Method: Female C57BL/6 mice were fed either HF (HF: 45% kcal fat) or control diet (C: 7% kcal fat) 6 weeks before mating and throughout pregnancy and lactation. Male and female offspring were fed C or HF diet from weaning (CC: n=8-10; CHF: n=4-12; HFC: n=9-12; HFHF: n=7-8/sex). In 52-week offspring, anxiety markers (distance travelled in centre [DTC] and entries to centre [EC]; open field test) and basal plasma ACTH concentrations (ELISA) were measured. Adrenal glands, cortex area, nuclei density (H&E) and lipid content (Oil Red O) were measured (ImageJ). Data were analysed by mixed effects model (SPSS).
Results: In males and females, maternal HF and postweaning HF diet increased anxiety (reduced DTC: maternal P<0.05, postweaning P<0.01; reduced EC: postweaning P<0.001). Postweaning HF diet increased cortex area in males and females (P<0.01, P<0.001, respectively), without any change in nuclei density. In females only, postweaning HF diet increased basal ACTH concentrations (P<0.01) and adrenal lipid content (P<0.05). Maternal HF diet did not affect offspring adrenal cortex area or lipid content.
Conclusions: These finding suggest that maternal and postweaning HF diet increase the risk of anxiety, which becomes apparent with advancing age. Postweaning, but not maternal, HF diet was associated with expansion of the adrenal cortex due to hyperplasia. This could contribute to the elevated basal corticosterone we previously observed in these animals and to their anxiety. In females, the increase in adrenal cortex area following postweaning HF diet could be driven by elevated ACTH concentrations and was associated with adrenal lipid content, which may impair normal adrenal functio
The role of adrenal morphology in high fat diet-induced anxiety in mature adult mice
No full textBackground/Aims: We have shown effects of both maternal and postweaning HF diet-induced obesity to increase anxiety and corticosterone output in mature adult mice, suggesting changes in the regulation of the hypothalamo-pituitary adrenal (HPA) axis. The current study investigated glucocorticoid (GR) and mineralocorticoid (MR) receptors in key brain regions of these mice, as well as FKBP51, a negative modulator of these receptors that is associated with anxiety-related disorders.
Method: Female C57BL/6 mice were fed either HF (HF: 45% kcal fat) or control diet (C: 7% kcal fat) 6 weeks before mating and throughout pregnancy and lactation. Male and female offspring were fed C or HF diet from weaning (3 weeks) (CC: n=7-8; CHF: n=4-7; HFC: n=7-9; HFHF: n=6-8/sex). In 52-week offspring brain (hippocampus [CA3] and hypothalamus [PVN]), GR, MR and FKBP51 mRNA levels were measured (RT-PCR). Data were analysed by mixed effects model (SPSS).
Results: In 52 week males, maternal HF diet reduced MR (P<0.001) and increased FKBP51 (P<0.01) in CA3. Postweaning HF diet also increased FKBP51 (P<001) in CA3 in males. In females, postweaning HF diet reduced MR (P<0.01) in CA3 but increased MR (P<0.05) and FKBP51 (P<0.001) in PVN. GR was unaffected in either sex by maternal or postweaning HF diet in PVN or CA3.
Conclusions: Changes in key factors in feedback mechanisms of the HPA axis in the mature adult brain suggest that maternal and postweaning HF diets may have long-term effects on stress responsiveness in a sex-specific manner. The increase in FKBP51 in both males and females following postweaning HF diet could be linked to the increased basal corticosterone we have previously observed in these animals, contributing to their heightened anxiety
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
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
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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