Lifetime Dependent Variation of Stress Hormone Metabolites in Feces of Two Laboratory Mouse Strains.

Non-invasive measurement of stress hormone metabolites in feces has become routine practice for the evaluation of distress and pain in animal experiments. Since metabolism and excretion of glucocorticoids may be variable, awareness and adequate consideration of influencing factors are essential for accurate monitoring of adrenocortical activity. Reference values are usually provided by baselines compiled prior to the experiment and by age matched controls.

Benefits of adversity?! How life history affects the behavioral profile of mice varying in serotonin transporter genotype.

Behavioral profiles are influenced by both positive and negative experiences as well as the genetic disposition. Traditionally, accumulating adversity over lifetime is considered to predict increased anxiety-like behavior ("allostatic load"). The alternative "mismatch hypothesis" suggests increased levels of anxiety if the early environment differs from the later-life environment.

Interaction of brain 5-HT synthesis deficiency, chronic stress and sex differentially impact emotional behavior in Tph2 knockout mice.

Rationale: While brain serotonin (5-HT) function is implicated in gene-by-environment interaction (GxE) impacting the vulnerability-resilience continuum in neuropsychiatric disorders, it remains elusive how the interplay of altered 5-HT synthesis and environmental stressors is linked to failure in emotion regulation.

Objective: Here, we investigated the effect of constitutively impaired 5-HT synthesis on behavioral and neuroendocrine responses to unpredictable chronic mild stress (CMS) using a mouse model of brain 5-HT deficiency resulting from targeted inactivation of the tryptophan hydroxylase-2 (Tph2) gene.

Results: Locomotor activity and anxiety- and depression-like behavior as well as conditioned fear responses were differentially affected by Tph2 genotype, sex, and CMS.

Effects of season, age, sex, and housing on salivary cortisol concentrations in horses.

Analysis of salivary cortisol is increasingly used to assess stress responses in horses. Because spontaneous or experimentally induced increases in cortisol concentrations are often relatively small for stress studies, proper controls are needed. This requires an understanding of the factors affecting salivary cortisol over longer times.

Immobilization stress sensitizes rat dorsal horn neurons having input from the low back.

Background: Stress is known to promote several forms of muscle pain including non-specific low back pain. However, the question if stress alone activates nociceptive central neurons has not been studied systematically. Here, we investigated the influence of repeated immobilization stress on dorsal horn neurons and behaviour in the rat.

Welfare and performance in layers following temporary exclusion from the litter area on introduction to the layer facility.

When introduced to the laying facility, pullets are sometimes temporarily excluded from the litter area in order to help them locate food and water, and to prevent floor-laid eggs. This procedure is not permitted in Sweden, because it involves denying access to both litter and space, which may have a negative effect on bird welfare. The present study investigated how the welfare and performance of layers were affected by this temporary exclusion on introduction of hens to the laying facility.

Stress assessment in small ruminants kept on city farms in southern Germany.

Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There are few data available on this type of usage of small ruminants. Health evaluations, behavioral observations (feeding, resting, comfort, explorative and social behaviors), behavioral tests (human approach tests and touch test), and measurements of fecal cortisol metabolites and heart rate were performed to assess stress levels in 25 sheep and 32 goats on 7 city farms and 2 activity playgrounds in Germany.

Impact of superovulation and mating on the wellbeing of juvenile and adult C57BL/6N mice.

Superovulation of mice is routinely used to increase the number of obtainable ova per female. Because of the better outcome, prepubescent females are preferentially used. Here, we provide results of the impact of superovulation and mating on the wellbeing of juvenile compared with adult C57BL/6N mice.

Contrasting stress responses of two co-occurring chipmunk species (Tamias alpinus and T. speciosus).

Glucocorticoid (GC) hormones are important mediators of responses to environmental conditions. Accordingly, differences in GC physiology may contribute to interspecific variation in response to anthropogenically-induced patterns of climate change. To begin exploring this possibility, we validated the use of fecal cortisol/corticosterone metabolites (FCM) to measure baseline glucocorticoid levels in two species of co-occurring chipmunks that have exhibited markedly different patterns of response to environmental change.

Assessment and refinement of intra-bone marrow transplantation in mice.

Intra-bone marrow transplantation (IBMT) may improve the seeding efficiency of transplanted hematopoietic stem cells compared to the routinely used intravenous injection. Current IBMT protocols are optimized for ease of use and to improve experimental results. However, there have been no investigations to assess the impact of IBMT on animal welfare.

Benefits of a ball and chain: simple environmental enrichments improve welfare and reproductive success in farmed American mink (Neovison vison).

Can simple enrichments enhance caged mink welfare? Pilot data from 756 sub-adults spanning three colour-types (strains) identified potentially practical enrichments, and suggested beneficial effects on temperament and fur-chewing. Our main experiment started with 2032 Black mink on three farms: from each of 508 families, one juvenile male-female pair was enriched (E) with two balls and a hanging plastic chain or length of hose, while a second pair was left as a non-enriched (NE) control. At 8 months, more than half the subjects were killed for pelts, and 302 new females were recruited (half enriched: 'late E').

Does hierarchy stability influence testosterone and cortisol levels of bearded capuchin monkeys (Sapajus libidinosus) adult males? A comparison between two wild groups.

Testosterone and cortisol are hormones expected to play a major role in competitive behaviours (i.e. aggression), and are related to rank and hierarchical stability.

Accumulation of radioactivity after repeated infusion of 3H-adrenaline and 3H-noradrenaline in the rat as a model animal.

Besides enzymatic inactivation, catecholamines bind non-enzymatically and irreversible to proteins. The physiological impact of these catecholamine adducts is still unclear. We therefore collected basic data about the distribution of catecholamine adducts in the rat after repeated intravenous administration of (3)H-adrenaline and (3)H-noradrenaline.

Mice selected for extremes in stress reactivity reveal key endophenotypes of major depression: a translational approach.

Clear evidence has linked dysregulated hypothalamus-pituitary-adrenocortical (HPA) axis function to the aetiology and pathophysiology of major depression (MD), as observed in the majority of patients. Increased stress reactivity and hyperactivity of the HPA axis seem characteristic for psychotic/melancholic depression, while the atypical subtype of depression has been connected with the opposing phenotypes. However, the underlying molecular-genetic mechanisms are poorly understood.

Temporal dynamic of adrenocortical and gonadal photo-responsiveness in male Japanese quail exposed to short days.

The study evaluated whether different short-term endocrine testicular and adrenocortical responses to short photoperiod exposure can persist over time and particularly when birds exhibit spontaneous cloacal gland recovery. At 11 wk of age, 33 male Japanese quail exposed to long photoperiod were switched to short photoperiod (8L:16D). Another group of males was kept under long photoperiod (n = 11; LD quail).

Physiological response to etho-ecological stressors in male Alpine chamois: timescale matters!

From a life history perspective, glucocorticoids secreted by the neuroendocrine system, integrating different sources of stress through an adaptive feedback mechanism, may have important consequences on individual fitness. Although stress responses have been the object of several investigations, few studies have explored the role of proximate mechanisms responsible for the potential trade-offs between physiological stress and life history traits integrating social and environmental stressors. In 2011 and 2012, we collected data on faecal cortisol metabolites (FCM) in a marked male population of Alpine chamois, within the Gran Paradiso National Park (Italy).

Mouse social stress induces increased fear conditioning, helplessness and fatigue to physical challenge together with markers of altered immune and dopamine function.

In neuropsychiatry, animal studies demonstrating causal effects of environmental manipulations relevant to human aetiology on behaviours relevant to human psychopathologies are valuable. Such valid models can improve understanding of aetio-pathophysiology and preclinical discovery and development of new treatments. In depression, specific uncontrollable stressful life events are major aetiological factors, and subsequent generalized increases in fearfulness, helplessness and fatigue are core symptoms or features.

Genetic interactions with sex make a relatively small contribution to the heritability of complex traits in mice.

The extent to which sex-specific genetic effects contribute to phenotypic variation is largely unknown. We applied a novel Bayesian method, sparse partitioning, to detect gene by sex (GxS) and gene by gene (GxG) quantitative loci (QTLs) in 1,900 outbred heterogeneous stock mice. In an analysis of 55 phenotypes, we detected 16 GxS and 6 GxG QTLs.

Environmental enrichment alters splenic immune cell composition and enhances secondary influenza vaccine responses in mice.

Chronic stress has deleterious effects on immune function, which can lead to adverse health outcomes. However, studies investigating the impact of stress reduction interventions on immunity in clinical research have yielded divergent results, potentially stemming from differences in study design and genetic heterogeneity, among other clinical research challenges. To test the hypothesis that reducing glucocorticoid levels enhances certain immune functions, we administered influenza vaccine once (prime) or twice (boost) to mice housed in either standard control caging or environmental enrichment (EE) caging.

Are motorways potential stressors of roadside wood mice (Apodemus sylvaticus) populations?

Linear infrastructures represent one of the most important human impacts on natural habitats and exert several effects on mammal populations. Motorways are recognized as a major cause of habitat fragmentation and degradation and of biodiversity loss. However, it is unknown whether motorways lead to increased physiological stress reactions in wild animal populations.

Development of an optimal diaphragmatic hernia rabbit model for pediatric thoracoscopic training.

Our objectives were to standarize the procedure needed to reproduce a similar surgical scene which a pediatric surgeon would face on repairing a Bochdalek hernia in newborns and to define the optimal time period for hernia development that achieve a realistic surgical scenario with minimimal animal suffering. Twenty New Zealand white rabbits weighing 3-3.5 kg were divided into four groups depending on the time frame since hernia creation to thoracoscopic repair: 48 h, 72 h, 96 h and 30 days.

Estrus cycle status defined by vaginal cytology does not correspond to fluctuations of circulating estrogens in female mice.

Gender-oriented studies in shock, trauma, and/or sepsis require accurate monitoring of hormonal fluctuations as estrogens may influence various end points. Yet, monitoring is challenging in small laboratory animals: e.g.

Photoperiodic effects on reproductive development in male cavies (Cavia aperea).

Age at maturity is a particularly important life history parameter, as it predicts potential life time reproductive success in many small mammal species. Animals should therefore optimize the timing of maturation by reacting to environmental stimuli that predict future environmental conditions. Photoperiod often reliably predicts ecological conditions.

Assessment of adrenocortical activity and behavior of the collared anteater (Tamandua tetradactyla) in response to food-based environmental enrichment.

One of the current standard approaches to the study of animal welfare is measuring hypothalamic-pituitary-adrenal activity, frequently in association with behavioral assessment. We studied the effects of food-based environmental enrichment on adrenocortical activity and behavior in zoo-housed collared anteaters (Tamandua tetradactyla; n = 5). We successfully validated measurements of fecal cortisol metabolites (FCMs) using an 11-oxoetiocholanolone enzyme immunoassay by stimulating (ACTH injection) and suppressing (dexamethasone administration) adrenocortical activity.