3 Minute 3Rs podcast: January 2023 transcript

[NC3Rs]

Happy New Year to all 3 Minute 3Rs listeners. It’s 2023, and we’re back with three more papers highlighting efforts to replace, reduce and refine the use of animals in research. To start the year, let’s begin with that first R and efforts to move towards non-animal reagents and components

[NA3RsC]

In scientific research, animal-derived components are often used in cell culture and laboratory practices. This use can be concerning due to ethical issues for the animals that produce these materials, variability and reproducibility. A potential solution is to use non-animal materials and reagents, as encouraged by many guiding agencies and documents. 

A recent publication in Engineering in Life Sciences describes results from a survey that was conducted to understand the current use of animal-derived reagents and obstacles for implementation. The authors found that the most commonly used animal derived reagents were serum, antibodies, and enzymes. Additionally, most respondents believed that their own awareness and knowledge about replacements was not adequate. 

These findings point to the importance of increasing awareness and promoting use of replacements for animal derived reagents. Current resources and proposals for these efforts can be found in the full publication. Learn more online. 

[NC3Rs]

Next up, a training technique for in utero microinjections

[Lab Animal]

In utero electroporation is a technique developed to introduce plasmid DNA into embryonic mouse brains, while the animals are in the uterus. The technique is a powerful tool to study brain development, function and disease, but learning how to perform the necessary microinjection is challenging and requires a long training period, together with the use of many animals.

To help reduce the numbers of animals used for training, Nadine Baumgart’s team at the University Medical Center of the Johannes Gutenberg-University developed a 3D printed simulator to practice in utero electroporation in mice. Using computed tomography coupled with 3D printing, the investigators created silicone models of mouse embryos and uterus with similar dimensions and mechanical properties to their natural counterparts.

Following a practical session, users gave the 3D simulator a favorable rating for providing a good introduction to in utero electroporation, which suggests that implementing simulators in the initial training stages could assist beginners in acquiring basic knowledge about the technique and reduce the number of animals for training.

To learn more about this study, read the full paper in Plos One.  

[NC3Rs]

Finally, a non-aversive method to encourage mice on a CatWalk

Investigating gait, the way an animal moves during locomotion, is an important tool in assessing the impact of various neurological conditions. The CatWalk system from Noldus allows for detailed gait analysis in mice but requires running at a constant, and ideally high, speed across a glass plate to capture foot falls.

Dickmann and colleagues have recently demonstrated that clicker training can be used to ensure this without the use of aversive stimuli such as air puffs.

Male and female mice were gradually taught to follow a target stick, initially in the home cage and then on the CatWalk system itself, using a click that had previously been associated with a reward.

During testing, mice were then left to run freely on the CatWalk system. Those that had undergone clicker training had both an increased running speed and required fewer trials to collect data. Clicker trained animals also showed decreased levels of anxiety in the open field and elevated plus maze tests, suggesting that clicker training can be used to both improve performance on the CatWalk system and have a positive impact on animal welfare.

For more details, you can read the full paper in the journal Animals by following the link in the description.

That’s all for January, we’ll be back next month for more 3Rs highlights. 3 Minute 3Rs is brought to you by Lab Animal, the North American 3Rs Collaborative, and the NC3Rs. Thanks for listening, and don’t forget to listen next month for more 3Rs research.