Chronic pain, which affects the lives of approximately 20% of the population, is a public health problem and priority. Although small animal models have greatly contributed to our understanding of pain mechanisms, research in rodents has often failed to deliver novel effective treatments. Large animal models, more similar to humans, could facilitate the successful translation of bench observations into clinical applications. A new Review discusses available pig models for pain research, and compares them in term of intensity and duration. The Review also discusses how improved pain assessment methods may be the key to a successful pig-to-human translation.

See Meijs et al.

We’ve gone retro this month to celebrate Lab Animal’s 50th Anniversary! 1971 saw the very first issue of the long-running journal, which has grown to encompass animal research from vivarium to lab bench and everywhere in between and features an ever-growing menagerie of model species. Here’s to 50 more years!

See Editorial

Animals move. Keeping track of that can help researchers answer questions across a number of scientific disciplines, but it’s a tedious task to watch and annotate hours of videos of mice and worms and zebrafish (and more!) moving about for analysis. Can software help? A new Review compares and contrasts 28 different tracking software applications for different model species to help inform what option might be the best one for the question you want to ask of your animals.

See Panadeiro et al.

If animal activity is your measure, you need a good baseline against which to compare any changes following an experimental invention. Home cages that can automatically track the motion of the mice within can provide such information. A new research article this month uses an automated home cage tracking device to establish baseline activity for three mouse strains, highlighting differences in locomotor patterns and underscoring the need to know the basics about the model you are working with.

See Fuochi et al.

Behavioral neuroscience requires subjects that can, well, behave. Animals will remain important in this discipline, but that doesn’t mean there aren’t ways to improve their welfare while they are being studied. Touchscreen technologies are one way researchers interested in the behavior of their animals can also implement the 3Rs – at least on a relative basis. A new Review this month touches on the Relative Replacement-, Refinement-, and Reduction-related benefits that touchscreens can offer those working with nonhuman primates and rodents.

SeeLopez-Cruz et al.

Before drugs and drug delivery systems are approved, they need to be tested for both safety and in vivo efficacy. To help reduce and replace the number of rodents needed for such work, many researchers have been exploring alternative models that can still yield important biological information.

An emerging experimental option can be found within the incredible egg. A new comment this month discusses the advantages and limitations of the chick embryo for drug testing.

See Fonseca et al.

Caenorhabditis elegans may be a relatively simple organism on its own, but it nevertheless plays host to unique and diverse microbial communities of even small microorganisms. The various tools available to manipulate both the worm and its various microbial residents make C. elegans a valuable biosensor in which to probe the intricacies of host-microbe interactions, which can yield important insight into such relationships in more complex organisms, including humans. The microbiome field has much to learn from the worm as a model.

See Cabreiro et al.

Strokes that occur in the human brainstem are often lethal; if patients do survive, they are usually left with severe cognitive and/or motor disabilities. Animal models are critical to understanding and treating stroke, but targeting different areas of the brain, such as the brainstem, can be difficult. A new Protocol this month details the steps to induce a focal infarction in the rat brainstem.

See Namioka et al.

The micropipette-guided drug administration (MDA) method was originally developed as a less-stressful alternative to oral gavage for delivering drugs to laboratory mice. New research published this month evaluates the MDA approach as a non-invasive alternative to intraperitoneal injections to deliver ligands for DREADD systems, a chemogenetic technique for manipulating neuronal activity in behaving animals.

See Schalbetter et al.

To induce pseudopregnancy in female mice, they need to be mated with males that are sterile and can’t cause actual pregnancy. Sterility can be achieved through surgical vasectomy or the use of genetically modified males but in the former case, there can be pain and discomfort involved and in the latter, unusable animals. A new research article proposes a potential refinement and reduction for inducing pseudopregnancy: mating females with naturally sterile hybrid male mice.

See Preece et al.

The effects of anesthetics on an animal are important considerations for both animal welfare and scientific research, with consequences for how researchers interpret results with their subjects. Isoflurane, for example, has long been thought to cause cardiovascular depression in mice. A new research article revisits this anesthetic, exploring a variety of different measures in search of the effects of isoflurane on cardiovascular function.

See Poon et al.