Assessment of the effect of tricaine (MS-222)-induced anesthesia on brain-wide neuronal activity of zebrafish () larvae.

Fast and effective anesthesia is the key for refining many invasive procedures in fish and gaining reliable data. For fish as for all vertebrates, it is also required by European law to reduce pain, suffering, and distress to the unavoidable minimum in husbandry and experiments. The most often used substance to induce anesthesia in zebrafish is tricaine (MS-222).

Assessing spatial learning and memory in mice: Classic radial maze versus a new animal-friendly automated radial maze allowing free access and not requiring food deprivation.

The radial arm maze (RAM) is a common behavioral test to quantify spatial learning and memory in rodents. Prior attempts to refine the standard experimental setup have been insufficient. Previously, we demonstrated the feasibility of a fully automated, voluntary, and stress-free eight-arm RAM not requiring food or water deprivation.

Repeatability analysis improves the reliability of behavioral data.

Reliability of data has become a major concern in the course of the reproducibility crisis. Especially when studying animal behavior, confounding factors such as novelty of the test apparatus can lead to a wide variability of data which may mask treatment effects and consequently lead to misinterpretation. Habituation to the test situation is a common practice to circumvent novelty induced increases in variance and to improve the reliability of the respective measurements.

Automated radial 8-arm maze: A voluntary and stress-free behavior test to assess spatial learning and memory in mice.

The radial arm maze (RAM) is a common behavioral test to assess spatial working and reference memory in mice. However, conventional RAM experiments require a substantial degree of manual handling and animals are usually subjected to prolonged periods of food or water deprivation to achieve sufficient learning motivation resulting in stress-induced confounding effects and unwanted intra- and inter-subject variation. In a proof-of-concept approach to improve reliability and repeatability of results by refining the conventional maze methodology, we developed a voluntary, fully automated 8-arm RAM and tested its feasibility and usability using both spatial working and combined working/reference memory paradigms in ten female C57BL/6J mice.

Refining humane endpoints in mouse models of disease by systematic review and machine learning-based endpoint definition.

Ideally, humane endpoints allow for early termination of experiments by minimizing an animal's discomfort, distress and pain, while ensuring that scientific objectives are reached. Yet, lack of commonly agreed methodology and heterogeneity of cut-off values published in the literature remain a challenge to the accurate determination and application of humane endpoints. With the aim to synthesize and appraise existing humane endpoint definitions for commonly used physiological parameters, we conducted a systematic review of mouse studies of acute and chronic disease models, which used body weight, temperature and/or sickness scores for endpoint definition.

Body temperature measurement in mice during acute illness: implantable temperature transponder versus surface infrared thermometry.

Body temperature is a valuable parameter in determining the wellbeing of laboratory animals. However, using body temperature to refine humane endpoints during acute illness generally lacks comprehensiveness and exposes to inter-observer bias. Here we compared two methods to assess body temperature in mice, namely implanted radio frequency identification (RFID) temperature transponders (method 1) to non-contact infrared thermometry (method 2) in 435 mice for up to 7 days during normothermia and lipopolysaccharide (LPS) endotoxin-induced hypothermia.

Combination effects of azole fungicides in male rats in a broad dose range.

Two 28-day feeding studies were performed in male rats to investigate combination effects of azole fungicides in a broad dose range. Following separate administration of cyproconazole, epoxiconazole, prochloraz, propiconazole, and tebuconazole at five dose levels, the first three compounds were selected to be administered in two different mixtures at three dose levels including very low doses. Here we present the data obtained by clinical observations, pathology, histopathology, clinical chemistry and haematology.

Heterosubtypic immunity to H7N9 influenza virus in isogenic guinea pigs after infection with pandemic H1N1 virus.

Heterosubtypic immunity is defined as immune-mediated (partial) protection against an influenza virus induced by an influenza virus of another subtype to which the host has not previously been exposed. This cross-protective effect has not yet been demonstrated to the newly emerging avian influenza A viruses of the H7N9 subtype. Here, we assessed the induction of protective immunity to these viruses by infection with A(H1N1)pdm09 virus in a newly developed guinea pig model.

Virus replication kinetics and pathogenesis of infection with H7N9 influenza virus in isogenic guinea pigs upon intratracheal inoculation.

Since 2013, avian influenza viruses of subtype H7N9 have been transmitted from poultry to humans in China and caused severe disease. Concerns persist over the pandemic potential of this virus and further understanding of immunity and transmission is required. The isogenic guinea pig model uniquely would allow for investigation into both.

Pathogenesis of infection with 2009 pandemic H1N1 influenza virus in isogenic guinea pigs after intranasal or intratracheal inoculation.

To elucidate the pathogenesis and transmission of influenza virus, the ferret model is typically used. To investigate protective immune responses, the use of inbred mouse strains has proven invaluable. Here, we describe a study with isogenic guinea pigs, which would uniquely combine the advantages of the mouse and ferret models for influenza virus infection.

Application of stable carbon isotope analysis to the detection of 17beta-estradiol administration to cattle.

The use of anabolic agents in food producing animals is prohibited within the EU since 1988 (96/22/EC directive). The control of the illegal use of natural steroid hormones in cattle is still an exciting analytical challenge as far as no definitive method and non-ambiguous analytical criteria are available. The ability of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to demonstrate the administration of 17beta-estradiol to bovine has been investigated in this paper.