1,721,093 research outputs found
Selective disruption of perineuronal nets in mice lacking Crtl1 is sufficient to make fear memories susceptible to erasure
No full textChondroitin sulphate proteoglycans in the extracellular matrix restrict plasticity in the adult central nervous system and their digestion with chondroitinase ABC reactivates plasticity. However the structures in the extracellular matrix that restrict plasticity are unknown. There are many changes in the extracellular matrix as critical periods for plasticity close, including changes in chondroitin sulphate proteoglycan core protein levels, changes in glycosaminoglycan sulphation and the appearance of dense chondroitin sulphate proteoglycan-containing perineuronal nets around many neurons. We show that formation of perineuronal nets is triggered by neuronal production of cartilage link protein Crtl1 (Hyaluronan and proteoglycan link protein 1, Hapln1), which is upregulated in the visual cortex as perineuronal nets form during development and after dark rearing. Mice lacking Crtl1 have attenuated perineuronal nets, but the overall levels of chondroitin sulphate proteoglycans and their pattern of glycan sulphation are unchanged. Crtl1 knockout animals retain juvenile levels of ocular dominance plasticity and their visual acuity remains sensitive to visual deprivation. Therefore, the organization of chondroitin sulphate proteoglycan into perineuronal nets is the key event in the control of central nervous system plasticity by the extracellular matrix. In addition, using chondroitinase ABC treatment targeting chondroitin sulfate proteoglycans, previous studies showed that the maturation of the extracellular matrix makes fear memories resistant to deletion. Since mice lacking the cartilage link protein Crtl1 display normal chondroitin sulfate proteoglycans levels but impaired chondroitin sulfate proteoglycans condensation in perineuronal nets, we asked whether the presence of perineuronal nets in the adult brain is responsible for the appearance of persistent fear memories by investigating fear extinction in Crtl1-KO mice. We found that mutant mice displayed fear memory erasure after an extinction protocol as revealed by analysis of freezing and pupil dynamics. Fear memory erasure did not depend on passive loss of retention. Moreover, we demonstrated that, after extinction training, conditioned Crtl1-KO mice display no neural activation in the amygdala (Zif268 staining) in comparison to control animals. Taken together, our findings suggest that the aggregation of chondroitin sulfate proteoglycans into perineuronal nets regulates the boundaries of the critical period for fear extinction
Prevention and Treatment of Atherosclerosis: The Use of Nutraceuticals and Functional Foods
Full text linkNutritional interventions are effective and - in theory - easy to implement primary and secondary prevention strategies that reduce several risk factors of atherosclerosis and cardiovascular disease (CVD). Yet, because of (a) the severe impact of CVD in terms of mortality, morbidity, quality of life, and economy, (b) the proved role of LDL plasma concentrations as the most critical risk factor, and (c) the obstacles found both in terms of biological effects and compliance of the patient by an exclusively dietary intervention, food supplements or nutraceuticals are now valuable resources for physicians. As regards cholesterol control, several preparations are available in the market, and we will critically review them in this chapter
Omega 6 fatty acids: helpful, harmless or harmful?
No full textPurpose of review This paper reviews the most recent literature from January 2023 to August 2024 on the physiological effects of n-6 polyunsaturated fatty acids (PUFAs), with a focus on linoleic acid (LA).Recent findings Contrary to previous concerns that high LA intake may increase inflammation, most recent evidence supports the benefits of LA for cardiometabolic health.Several large studies report that higher blood LA levels correlate with reduced risks of coronary heart disease, stroke, and type 2 diabetes.Potential mechanisms include activation of peroxisome proliferator-activated receptors and modulation of oxylipins involved in glucose and lipid metabolism.The ideal LA intake level remains uncertain, but current intakes around 5-10% of energy appear beneficial.In other areas like cancer, asthma and sleep, the evidence is still inconclusive on LA's effects.Summary More research on diverse populations is needed to determine optimal LA levels, effects on specific conditions, and int..
Moderate alcohol use and health: An update a Consensus Document
No full textExcessive alcohol consumption is associated with increased incidence of several degenerative diseases and ill health. However, in 2013, Poli et al. published a Consensus document in which they thoroughly and critically reviewed all available evidence in support (or against) the moderate and alimentary use of alcohol. We added further evidence to the aforementioned by searching and selecting according to relevance and novelty the recent literature on alcohol and health, published since the appear- ance of that paper and conclude that it appears convenient to educate consumers and health professionals on the appropriate use of alcoholic beverages, within the framework of a healthy lifestyle
Dietary advice to cardiovascular patients. A brief update for physicians
Full text linkIt is important, in our opinion, to provide physicians with a brief update of scientifically-sound evidence in preventive nutrition, to be employed in their everyday practice, since the latest scientific and clinical advances in this area are generally not well known. Here, we review the most recent evidence in support of an optimal cardio-protective diet, and we identify the need to focus mainly on protective food which should be part of such diet, rather than on nutrients with negative effects to be limited (salt, saturated fats, simple sugars). We conclude that, to favor patient compliance, it is also necessary to underscore indications on the topics for which there is convincing and coherent literature, leaving other less-explored aspects to individual preferences
Fatty Acids and Cardiovascular Risk. Evidence, Lack of Evidence, and Diligence
Full text linkOne of the most controversial areas of nutrition research relates to fats, particularly essential fatty acids, in the context of cardiovascular disease risk. A critical feature of dietary fatty acids is that they incorporate into the plasma membrane, modifying fluidity and key physiological functions. Importantly, they can reshape the bioavailability of eicosanoids and other lipid mediators, which direct cellular responses to external stimuli, such as inflammation and chronic stress conditions. This paper provides an overview of the most recent evidence, as well as historical controversies, linking fat consumption with human health and disease. We underscore current pitfalls in the area of fatty acid research and critically frame fatty acid intake in the larger context of diet and behavior. We conclude that fundamental research on fatty acids and lipids is appropriate in certain areas, but the rigor and reproducibility are lacking in others. The pros and cons are highlighted throughout the review, seeking to guide future research on the important area of nutrition, fat intake, and cardiovascular disease risk
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
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