O mouse, where art thou? The Mouse Position Surveillance System (MoPSS)-an RFID-based tracking system

Existing methods for analysis of home cage-based preference tests are either time-consuming, not suitable for group management, expensive, and/or based on proprietary equipment that is not freely available. To correct this, we developed an automated system for group-housed mice based on radio frequency identification: the Mouse Position Surveillance System (MoPSS). The system uses an Arduino microcontroller with compatible components; it is affordable and easy to rebuild for every laboratory because it uses free and open-source software and open-source hardware with the RFID readers as the only proprietary component. The MoPSS was validated using female C57BL/6J mice and manual video comparison. It proved to be accurate even for fast-moving mice (up to 100% accuracy after logical reconstruction), and is already implemented in several studies in our laboratory. Here, we provide the complete construction description as well as the validation data and the results of an example experiment. This tracking system will allow group-based preference testing with individually identified mice to be carried out in a convenient manner. This facilitation of preference tests creates the foundation for better housing conditions from the animals' perspective.

Micro- and Macroenvironmental Conditions and Stability of Terrestrial Models

Environmental variables can have profound effects on the biological responses of research animals and the outcomes of experiments dependent on them. Some of these influences are both predictable and unpredictable in effect, many are challenging to standardize, and all are influenced by the planning and conduct of experiments and the design and operation of the vivarium. Others are not yet known. Within the immediate environment where the research animal resides, in the vivarium and in transit, the most notable of these factors are ambient temperature, relative humidity, gaseous pollutant by-products of animal metabolism and physiology, dust and particulates, barometric pressure, electromagnetic fields, and illumination. Ambient temperatures in the animal housing environment, in particular those experienced by rodents below the thermoneutral zone, may introduce degrees of stress and thermoregulatory compensative responses that may complicate or invalidate study measurements across a broad array of disciplines. Other factors may have more subtle and specific effects. It is incumbent on scientists designing and executing experiments and staff responsible for animal husbandry to be aware of, understand, measure, systematically record, control, and account for the impact of these factors on sensitive animal model systems to ensure the quality and reproducibility of scientific studies.

Housing breeding mice in three different IVC systems: maternal performance and pup development

A proper cage environment is essential for the welfare of laboratory mice, especially for females during the energy demanding lactation period and for pups during early development and growth. The most common housing system for laboratory mice is individually ventilated cages (IVCs) of which there are different layouts and ventilation strategies available on the market. The present study investigates the impact of cage environment in three different IVC types, on the maternal performance of females, and pup development and growth in C57BL/6NCrl and Crl:NMRI Foxn1 ^nu mice. The results show differences in in-cage climate, female body weight, pup growth, feed and water consumption, and nest quality between cage types. There was a distinct effect of genotype in these differences, with the main effects found in NMRI NU mice. The results indicate that IVC systems might need to be managed differently for mice of different types and/or different physiological status. Many of the differences seen between cage systems could be drawn to the physical construction of the cage, such as location of feed hopper and location of air inlet and outlet. In conclusion, IVC in-cage climate affects the maternal performance of female mice and pup growth, but with differences between the two strains tested.