Mice are widely used in scientific research, but is this truly a random choice, or are there specific factors that make them ideal?
The History and Ethics of Lab Rodents
According to Smithsonian Magazine, rats and mice have been used for scientific research since the 1850s and early 1900s, respectively. They are actually protected by a variety of ethical regulations concerning animal testing. These regulations ensure that lab mice are only used when truly necessary. Additionally, scientists often go to great lengths to ensure these mice are comfortable. For instance, researchers stopped holding mice by their tails after studies showed it caused stress to the animals, as reported by
Smithsonian Magazine.
The Scientific Advantages of Using Mice
The factors that truly influence why rats and mice are used in research are actually quite complex and scientifically sound. Factors considered include the animals’ temperament, their high genetic similarity to humans, and their good reproductive rates, according to Live Science.
Unlike larger animals, mice reproduce quickly, according to Live Science. Their gestation period lasts only about three weeks, and within just six weeks, the pups can develop into sexually mature adults. This means that multiple generations of mice can be studied within a single research program, allowing scientists to examine how genetic traits are passed down through generations.
Furthermore, mice are small in size and easily domesticated, so scientists generally don’t encounter overly complex problems when using them. Additionally, they are quite adaptable creatures, able to acclimate to various environments, including the often strange conditions of a laboratory.
What’s more, mice are also quite inexpensive, helping to reduce research costs.
Genetic Similarities and Modifiability
However, one important point is to remember that mice are not primates. While primates have a very close genetic resemblance to humans (up to 95% similar, one could say), the use of primates in research remains highly controversial. It’s also worth noting that mouse genes are very easy to modify.
This means that scientists can manipulate mice so that certain genes are inactivated or “knocked out.” They call these manipulated mice “knockout mice,” and they are beneficial for researchers who are focused on understanding what diseases a certain gene might cause. By knocking out a gene in some mice and keeping it active in others, scientists can figure out how that gene contributes to disease in humans.
Another type of modified rodent is the transgenic mouse. These are bred to have foreign DNA inserted into their genome. This is a very effective way to model specific diseases affecting humans and to study genetic functions.
The Legacy of Research and Ethical Considerations
And consider this: science is also a field built and developed upon past works. As we’ve mentioned, the use of mice in laboratories is incredibly common and has grown exponentially; this growth might be a reason for the mice’s popularity in experiments. If a scientist chooses to use a certain animal in an experiment, that animal will often be chosen again when conducting similar or related experiments.
As the most common experimental animal, mice have helped humans achieve many scientific breakthroughs. What these animals experience daily in laboratories is largely unknown to the general public.
It’s not just anyone who wants to can use mice in experiments. Scientists must undergo training in animal ethics and handling protocols before being allowed to “work” with them in the laboratory. Handling rules vary by country. In Canada and Europe, scientists are supervised by a national regulatory body; in the US, they must comply with individual institutional regulations and general guidelines from the National Institutes of Health.
Most universities in the US offer training courses on how to treat mice to minimize stress and pain during experiments. The adopted procedures are updated annually to align with humanity’s evolving understanding of mouse welfare.
