Claudia Wolschrijn, anatomist within the Pathobiology department at the faculty of Veterinary Medicine at Utrecht University, was awarded a grant from the 3Rs Stimulus Fund of Utrecht University for her research on making air sacs visible in prepared birds. The goal of this project is to reduce the use of laboratory animals in education by making plastinates - animals or sections of animals prepared in a special way to preserve them over time.
Veterinary students can study a plastinated animal to learn about its anatomy in 3D. Formerly, every group of students needed a fresh animal cadaver, but the plastinates last for years. The animals that are plastinated at the department of Pathobiology have been either euthanized after an experiment or donated through the Animal Donor Codicil of the Dutch Society for the Replacement of Animal Testing.
Bird plastinates for a 3D mental picture
Birds have a remarkable structure. They don’t have a diaphragm; their lungs are next to the oviduct and they also have air sacs. It’s all hard for the students to imagine, which is why some birds like, for instance, chickens, are plastinated. But there is a problem with these air sacs. Wolschrijn: “The air in the sacs keeps them under pressure. If you cut into them, the pressure from the surrounding organs immediately empties them. But you don’t want those air sacs to disappear in the plastinate. We managed to fill the hollows in the air sacs with yellow latex, but that turns opaque so the students are just looking at a yellow blob and they can’t see which organs are behind them. That’s the problem we are trying to solve.”
Wolschrijn and her colleagues are still in early days with this particular project. “We had a brainstorming session about possible ways to plastinate the air sac better. We’ve tried out a few ideas, but we haven’t yet got the results we were hoping for,” says Wolschrijn. They were able to make the air sac stronger and put in a kind of flap so you can see through it in a few places, which is better, but not ideal. A few other test models are still in the process of being plastinated, which takes a few months altogether. Wolschrijn and her colleagues are waiting to see how successful those are.
This specialized research for the production of an accurate plastinated model is important for future veterinarians. A bird that needs to be examined or treated by a veterinarian has skin and feathers on the outside. The vet needs to have a 3D mental picture of how the inside looks. Textbooks have illustrations and descriptions, but providing a 3D plastinate completes the picture. Wolschrijn hopes that this will help the students to remember what they have learned better, and even that it teaches them to convert other pictures to 3D in their heads. In order to get to this 3D picture, the plastinated models have the potential to achieve the same learning goals as an animal cadaver. The big difference between these options is the number of animals needed to provide good quality education and training. Veterinary graduates may have to deal with birds in their work, depending on the direction they choose during their education. Students who opt for farm animal health can specialize in poultry. Vets who work with pets also get canaries, parakeets and parrots in their clinical practice, so they certainly do need to know about the anatomy of birds.
A plastinated chicken air sac
Chasing potential ideas thanks to the 3Rs Stimulus Fund
The grant from the 3Rs Stimulus Fund means a great deal to this research. Wolschrijn: “I had been thinking about reducing the number of chickens used in education, for a long time. The call for proposals was a reason to really sit down together as a group and think about it. You can’t easily say this study is going to work out fine. It’s mainly feeling our way along, seeing what works and what doesn’t.” At the department of Pathobiology, animals or sections of animals are plastinated on a daily basis; a cat, a dog, a pig, or a cow, for example. Because of the many things that need to be done in everyday work, it is difficult to prioritize a plan that is less likely to succeed. The grant helped Wolschrijn and her colleagues to take that step and perform a pilot study with the chicken air sacs in between working on other animals, even if the outcome is uncertain. Wolschrijn: “We just have to wait and see if we have found a good method, but if we do find one it will be a huge improvement. If the grant hadn’t come through, it would have remained one of those ideas that keeps gnawing at you.”