The male sex pheromone darcin stimulates hippocampal neurogenesis and cell proliferation in the subventricular zone in female mice

The integration of newly generated neurons persists throughout life in the mammalian olfactory bulb and hippocampus, regions involved in olfactory and spatial learning. Social cues can be potent stimuli for increasing adult neurogenesis; for example, odors from dominant but not subordinate male mice increase neurogenesis in both brain regions of adult females. However, little is known about the role of neurogenesis in social recognition or the assessment of potential mates. Dominant male mice scent-mark territories using urine that contains a number of pheromones including darcin (MUP20), a male-specific major urinary protein that stimulates rapid learned attraction to the spatial location and individual odor signature of the scent owner. Here we investigate whether exposure to darcin stimulates neurogenesis in the female brain. Hippocampal neurons and cellular proliferation in the lateral ventricles that supply neurons to the olfactory bulbs increased in females exposed for 7 days to male urine containing at least 0.5 μg/μl darcin. Darcin was effective whether presented alone or in the context of male urine, but other information in male urine appeared to modulate the proliferative response. When exposed to urine from wild male mice, hippocampal proliferation increased only if urine was from the same individual over 7 days, suggesting that consistency of individual scent signatures is important. While 7 days exposure to male scent initiated the first stages of increased neurogenesis, this caused no immediate increase in female attraction to the scent or in the strength or robustness of spatial learning in short-term conditioned place preference tests. The reliable and consistent stimulation of neurogenesis by a pheromone important in rapid social learning suggests that this may provide an excellent model to explore the relationship between the integration of new neurons and plasticity in spatial and olfactory learning in a socially-relevant context

Differential vascular dysfunction in response to diets of differing macronutrient composition: a phenomenonological study

<p>Abstract</p> <p>Background</p> <p>Vascular dysfunction can develop from consumption of an energy-rich diet, even prior to the onset of obesity. However, the roles played by different dietary components remain uncertain. While attempting to develop models of obesity in a separate study, we observed that two high-energy diets of differing macronutrient compositions affected vascular function differently in overweight rats.</p> <p>Methods</p> <p>Male Wistar rats (<it>n </it>= 6/group) were fed diets providing varying percentages of energy from fat and carbohydrate (CHO). For 10 weeks, they were fed either chow, as control diet (10% of energy from fat; 63% from CHO), chow supplemented with chocolate biscuit (30% fat; 56% CHO) or a high-fat diet (45% fat; 35% CHO). Blood concentrations of biochemical markers of obesity were measured, and epididymal fat pads weighed as a measure of adiposity. Mesenteric arteries were dissected and their contractile and relaxant properties analysed myographically. Data were tested by analysis of variance (ANOVA).</p> <p>Results</p> <p>Weight gain and plasma concentrations of glucose, insulin and leptin were similar in all groups. However, biscuit-fed animals showed increased food intake (+27%; <it>p </it>< 0.01) and elevated concentrations of TGs and NEFAs (+41% and +17%; both <it>p </it>< 0.05). High-fat-fed animals showed an increase only in NEFAs (+38%; <it>p </it>< 0.01). Arterial vasoconstriction in response to NA and KCl increased only in biscuit-fed rats (both <it>p </it>< 0.01), while vasorelaxation in response to CCh and SNP, but not histamine, was attenuated in both groups (both <it>p </it>< 0.01). Furthermore, whereas the effect of the high-fat diet was most pronounced in endothelium-dependent vasorelaxation, the biscuit diet had the greater effect on endothelium-independent vasorelaxation.</p> <p>Conclusion</p> <p>Vascular dysfunction resulting from consumption of a high-fat or combined relatively high-fat/high-CHO diet occurs through different physiological processes, which may be attributable to their differing macronutrient compositions. Combining potentially atherogenic macronutrients induces more extensive vascular impairment than that of high-fat alone, and may be attributable to the more marked dyslipidaemia observed with such a diet. Thus, these findings help clarify the role of dietary components in vascular impairment, which has implications for clinical approaches to preventing cardiovascular disease.</p

Altered Left Ventricular Ion Channel Transcriptome in a High-Fat-Fed Rat Model of Obesity: Insight into Obesity-Induced Arrhythmogenesis

Introduction. Obesity is increasingly common and is associated with an increased prevalence of cardiac arrhythmias. The aim of this study was to see whether in obesity there is proarrhythmic gene expression of ventricular ion channels and related molecules. Methods and Results. Rats were fed on a high-fat diet and compared to control rats on a normal diet (). After 8 weeks, rats on the high-fat diet showed significantly greater weight gain and higher adiposity. Left ventricle samples were removed at 8 weeks and mRNA expression of ion channels and other molecules was measured using qPCR. Obese rats had significant upregulation of , HCN4, , RYR2, NCX1, SERCA2a, and RYR2 mRNA and downregulation of ERG mRNA. In the case of HCN4, it was confirmed that there was a significant increase in protein expression. The potential effects of the mRNA changes on the ventricular action potential and intracellular Ca2+ transient were predicted using computer modelling. Modelling predicted prolongation of the ventricular action potential and an increase in the intracellular Ca2+ transient, both of which would be expected to be arrhythmogenic. Conclusion. High-fat diet causing obesity results in arrhythmogenic cardiac gene expression of ion channels and related molecules

Evaluation of innovative digital microscopy and interactive team-based learning approaches in histology teaching

Histology teaching in veterinary science and other higher education clinical programmes has traditionally relied on light microscopy in a laboratory setting. However, increasing student numbers, limited flexibility of these tools for learning outside the lab, and, most recently, the COVID-19 pandemic, are driving the search for alternative approaches to delivery and sustaining of learning resources. Improved digital technologies, increasingly available through technology-enhanced learning facilities, can help address these issues. Thus, we created a digitized, interactive library of slide-mounted tissue specimens accessible through our institutional virtual learning environment, piloted its uptake by first-year BVSc students, tested it in combination with a team-based learning/flipped classroom strategy, and compared old and new approaches by evaluating student preferences and histology examination results. Students reported greater engagement with the new resource which appeared to influence exam results positively. We identify future areas of investigation and suggest developments to these approaches to encourage adoption across curricula.</jats:p

Diet-induced endothelial dysfunction in the rat is independent of the degree of increase in total body weight

U ovome završnome radu objašnjava se tehničko–tehnološki razvoj i napredak djelovanja oklopne zaštite na borbenim oklopnim vozilima. Uvod rada govori o pojmu zaštite, odnosno o njegovoj pojavi, značenju i prvoj upotrebi. Zatim se uz naslov rada „Povijesni razvoj oklopne zaštite“ veže razvoj oklopne zaštite od prvog tenka do modernih tenkova. U nastavku prikazane su vrste oklopne zaštite te materijali koji su primjenjivani kod istih. Nakon toga se analiziraju Oružane snage Republike Hrvatske i njihova glavna oklopna borbena sredstva: tenk i borbeno vozilo pješaštva, te je predloženo moguće poboljšanje glavnog borbenog tenka M - 84. Na samom kraju je iznesen kratak zaključak ovog rada.This graduation paper explains and clarifies the technical and technological progress and development of armor protection on armored vehicles. The introduction of the paper is focused on the term of protection, its appearance, meaning and its first use. Then, related to the title of the paper "Historical Development of Armor Protection", the development of armored protection from the first tanks to the modern tanks is explained. In continuation, types of armor protection and the materials applied to them are presented. Afterwards, Croatian Armed Forces and their main armored combat equipment are analyzed: the tank and the infantry fighting vehicle. After that, possible improvement of the main battle tank M - 84 is suggested. At the very end of the paper, a brief conclusion of this paper is set out