A review of animal experiments has identified clear opportunities to improve how studies are designed and analysed, which could increase the reliability and impact of research using animals. 

Researchers from the University of Saskatchewan and the University of Calgary, Canada, analysed 120 studies published in 2022, conducted in North America and Europe and involving mice, rats and hamsters. They found that fewer than 2.5% of studies included key practices to reduce bias.  

Some of these practices are: 

• Randomisation – assigning animals to experimental groups by chance. 

• Blinding – ensuring researchers do not know, when recording results, which animals received which treatment, to prevent unconscious bias. 

• Controlling for cage effects – recognising that differences in housing, such as light, noise or enrichment, can affect behaviour and outcomes and control these effects with adequate experimental design and minimising variable factors. 

The authors recommend that academic institutions educate specialists in study design and analysis, who could work alongside biomedical researchers to make animal studies more reproducible and improve the contribution of animal research to medical progress. 

The paper, published in Scientific Reports, concluded: “Only through these concerted efforts can the biomedical research community improve reproducibility, uphold ethical standards in laboratory animal experiments and build the confidence in preclinical research that is crucial for the health of both animals and humans.” 

Researchers in France have discovered that stress during pregnancy can make the progeny susceptible to develop eczema, in a study using mice.  

Eczema is the most common chronic pediatric skin condition and causes itchy, scaly and flaky skin. Epidemiological studies have linked childhood eczema to maternal stress, but a biological explanation was unknown. 

Researchers at the National Institute of Health and Medical Research (Inserm) discovered that newborn mice born from mothers that experienced mild stress during pregnancy — by having their movement restrained and placed under light for short periods of time — were more likely to developed eczema than mice born from animals that were free to roam. 

By analysing the skin of the progeny, researchers found that a type of inflammatory cells called mast cells were altered in mice born from mothers that experienced stress during pregnancy, leading to itching and swelling. Using mice without mast cells, they found that even if their mothers were stressed during pregnancy the newborns did not develop eczema.  

If the same mechanism occurs in humans, these findings, published in Nature, could lead to new therapeutic approaches for childhood eczema. The discoveries additionally highlight the importance of stress management during pregnancy.