Prenatal stress decreases Bdnf expression and increases methylation of Bdnf exon IV in rats

There is ample evidence that exposure to stress during gestation increases the risk of the offspring to develop mood disorders. Brain-derived neurotrophic factor (Bdnf) plays a critical role during neuronal development and is therefore a prime candidate to modulate neuronal signaling in adult offspring of rat dams that were stressed during gestation. In the current study, we tested the hypothesis that alterations in Bdnf expression in prenatally stressed (PNS) offspring are mediated by changes in DNA methylation in exons IV and VI of the Bdnf gene. We observed decreased Bdnf expression in the amygdala and hippocampus of prenatally stressed rats both at weaning and in adulthood. This decrease in Bdnf expression was accompanied by increased DNA methylation in Bdnf exon IV in the amygdala and hippocampus, suggesting that PNS-induced reduction in Bdnf expression may, at least in part, be mediated by increased DNA methylation of Bdnf exon IV. Expression of DNA methyltransferases (Dnmt) 1 and 3a was increased in PNS rats in the amygdala and hippocampus. Our data suggest that PNS induces decreases in Bdnf expression that may at least in part be mediated by increased DNA methylation of Bdnf exon IV.     

Catheter ablation in children and young adults: is there an additional benefit from remote magnetic navigation?

Purpose

Although rare, children and young adults can suffer from significant cardiac arrhythmia, especially in the context of congenital malformations and after cardiac surgery.

Methods

A total of 62 patients (32 female, median age 20 years) underwent an invasive electrophysiology study between 2008–2011: half had normal cardiac anatomy, whereas the remaining patients had various types of congenital heart disease. All patients were treated using either conventional techniques (CVN) or remote magnetic navigation (RMN).

Results

Patients treated with the RMN system differed substantially from patients in the CVN group with respect to presence of congenital heart disease (67 % vs. 37 %), previous cardiac surgery (59 % vs. 20 %) or failed previous conventional ablation (22 % vs. 9 %), respectively. Although these more complex arrhythmias resulted in longer median procedure duration (180 vs. 130 min, p = 0.034), the median overall fluoroscopy exposure in the RMN group was significantly lower (4.1 vs. 5.2 min, p = 0.020). Clinical outcome was comparable in both groups without complications caused by the ablation.

Conclusions

Catheter ablation using remote magnetic navigation is safe and feasible in children and young adults and is especially valuable in patients with abnormal cardiac morphologies. RMN resulted in significantly lower radiation exposure compared with the conventional technique.     

Conspecific density and environmental complexity impact behaviour of turquoise killifish (Nothobranchius furzeri)

Fish models are essential for research in many biological and medical disciplines. With a typical lifespan of only 6 months, the Turquoise killifish (Nothobranchius furzeri) was recently established as a time- and cost-efficient model to facilitate whole-life and multigenerational studies in several research fields, including behavioural ecotoxicology. Essential information on the behavioural norm and on how laboratory conditions affect behaviour, however, is deficient. In the current study, we examined the impact of the social and structural environment on a broad spectrum of behavioural endpoints in N. furzeri. While structural enrichment affected only fish boldness and exploratory behaviour, fish rearing density affected the total body length, locomotor activity, boldness, aggressiveness and feeding behaviour of N. furzeri individuals. Overall, these results contribute to compiling a behavioural baseline for N. furzeri that increases the applicability of this new model species. Furthermore, our findings will fuel the development of improved husbandry protocols to maximize the welfare of N. furzeri in a laboratory setting.     

The effect of visitors on the behavior of zoo-housed western lowland gorillas (Gorilla gorilla gorilla)

Primates, especially apes, are popular with the public, often attracting large crowds. These crowds could cause behavioral change in captive primates, whether positive, neutral, or negative. We examined the impact of visitors on the behavior of six western lowland gorillas (Gorilla gorilla gorilla), observing the troop over 6 weeks during high season (4.5 hr/day, 35 days, May–July 2016). We used focal scan sampling to determine activity budget and enclosure usage, and focal continuous sampling to identify bouts of anxiety-related behavior (visitor-directed vigilance, self-scratching, and aggression). Both daily zoo-entry numbers (V_GATE) and instantaneous crowds at the exhibit (V_DENSITY) were measured. Overall, V_GATE had little effect across behaviors. However, consistent with the more acute time frame of measurement, V_DENSITY was a better predictor of behavior; at high crowd volumes, we observed significant group-level changes in activity budget (increased inactivity, increased locomotion, and decreased environment-related behaviors), increase in some anxiety-related behaviors, and decreased enclosure usage. Although contributing similar effects, it could not be determined if crowd numbers, composition, or noise most affected the troop, nor any chronic effects of exposure to large crowds. Nevertheless, our findings suggest that measures to minimize the impacts of large crowds at the exhibit would be beneficial. Furthermore, we highlight potential discrepancies between common methods for measuring visitor numbers: V_GATE is less sensitive to detecting visitor effects on behavioral indices than V_DENSITY. Future studies should appropriately match the biological time frame of welfare indicators and visitor measures used to ensure the reliability of findings.     

Nutritional composition of black soldier fly larvae feeding on agro-industrial by-products

Black soldier fly (BSF) larvae, Hermetia illucens L. (Diptera: Stratiomyidae), bio-convert organic side streams into high-quality biomass, the composition of which largely depends on the side stream used. In the present study, BSF larvae were reared on feed substrates composed of dried brewers’ spent grains, each supplemented with either water, waste brewer’s yeast, or a mixture of waste brewer’s yeast and cane molasses to obtain 12 different substrates: barley/water, barley/yeast, barley/yeast/molasses, malted barley/water, malted barley/yeast, malted barley/yeast/molasses, malted corn/water, malted corn/yeast, malted corn/yeast/molasses, sorghum-barley/water, sorghum-barley/yeast, and sorghum-barley/yeast/molasses. The crude protein, fat, ash, and mineral contents of the BSF larvae fed each feed substrate were quantified by chemical analyses. The effect of substrate, supplementation, and their interaction on crude protein, fat, and ash contents of BSF larval body composition was significant. Calcium, phosphorus, and potassium were the most abundant macrominerals in the larvae and their concentrations differed significantly among substrates. These findings provide important information to support the use of BSF larval meal as potential new source of nutrient-rich and sustainable animal feed ingredients to substitute expensive and scarce protein sources such as fishmeal and soya bean meal.     

A dynamic model linking cell growth to intracellular metabolism and extracellular by-product accumulation

Mathematical modeling of animal cell growth and metabolism is essential for the understanding and improvement of the production of biopharmaceuticals. Models can explain the dynamic behavior of cell growth and product formation, support the identification of the most relevant parameters for process design, and significantly reduce the number of experiments to be performed for process optimization. Few dynamic models have been established that describe both extracellular and intracellular dynamics of growth and metabolism of animal cells. In this study, a model was developed, which comprises a set of 33 ordinary differential equations to describe batch cultivations of suspension AGE1.HN.AAT cells considered for the production of α1-antitrypsin. This model combines a segregated cell growth model with a structured model of intracellular metabolism. Overall, it considers the viable cell concentration, mean cell diameter, viable cell volume, concentration of extracellular substrates, and intracellular concentrations of key metabolites from the central carbon metabolism. Furthermore, the release of metabolic by-products such as lactate and ammonium was estimated directly from the intracellular reactions. Based on the same set of parameters, this model simulates well the dynamics of four independent batch cultivations. Analysis of the simulated intracellular rates revealed at least two distinct cellular physiological states. The first physiological state was characterized by a high glycolytic rate and high lactate production. Whereas the second state was characterized by efficient adenosine triphosphate production, a low glycolytic rate, and reactions of the TCA cycle running in the reverse direction from α-ketoglutarate to citrate. Finally, we show possible applications of the model for cell line engineering and media optimization with two case studies.     

Animals in Schools: Processes and Strategies in Human-Animal Education

Abstract

In this study we tested the hypothesis that the process of training a non-human primate (NHP) affects it's general behavior patterns, outside of training. A group of Abyssinian colobus monkeys (Colobus guereza, n = 8), housed at Paignton Zoo, UK, were observed for four 12-day periods. Behaviors were noted prior to training, using positive reinforcement to achieve oral examinations, and each month for three months after training had started. These data were used to construct daily activity budgets and investigate social behaviors (both colobus–colobus and colobus–human). A comparison of these data (using doubly repeated measures MANOVAs) showed activity budget (F_(3,3) = 9.8, λ = 0.4, p < 0.001) and colobus-initiated interactions with people (F_(3,2) = 16.6, λ = 0.3, p < 0.001) differed significantly across the four observation periods. Resting behavior was negatively correlated with feeding behavior (Pearson: n = 56, r = -0.25, p < 0.05); this relationship was considered to be independent of the onset of training. The significant decline in colobus-initiated interactions with the public appeared to be a direct result of the training.

The results in this study showed that the implementation of training reduced colobus–human interactions. Two reasons are suggested in this paper to account for these unexpected results; either or both of these explanations may be true. The increased level of keeper–colobus interactions necessary for training may have acted to socialize the colobus to humans, so that they habituated to the general presence of humans. Equally, the training sessions may have provided the colobus with predictable interactions with humans that provided rewards, outside of which colobus-initiated interactions were not worthwhile.

Training in this situation was found to be beneficial for the colobus and did not adversely affect the behavior of the colobus outside of the training sessions. It is concluded that caution should be taken when instigating training as part of captive primate management, due to species differences and the paucity of studies that have quantified the impact of training on zoo primate biology. What is greatly needed is more studies which are able to empirically compare the biology (behavior and physiology) of zoo housed primates before and after training has been implemented.