In a small research room near the Ralph H. Johnson VA Medical Center in Charleston, a tiny black mouse scurries across a glowing green miniature walkway as it tries to return to a nest of other mice. With each step, a bright green footprint follows.

The walkway, formally called the "CatWalk," projects data onto a nearby computer screen where the mouse can be seen while its footprints are measured. The purpose of the experiment is to watch how the mouse applies pressure to each of its legs. Scientists hope to use this information to further fuel research into unique fractures commonly diagnosed among veterans.

Though non-invasive and seemingly simple, this research still requires extensive oversight from veterinary and scientific experts to be conducted. Everything must be approved — from the type of equipment used to the number of mice enlisted.

This level of oversight isn’t unique to animal research at the Charleston VA. Animal research across the country has long been a source of controversy and tension, from both outside activists and scientists who want to limit the use of animals in these settings as much as possible. With at least seven entities across the state, including the VA hospital in Charleston and the Medical University of South Carolina, certified to conduct animal research and nearly 3,000 animals currently in use, the Palmetto State finds itself very much a part of this national conversation.

“It’s very much limited, very restricted,” said Dr. R. Amanda LaRue, head of research at the VA hospital.

Nationally, Americans are almost evenly divided when it comes to their opinions of animal use in scientific research. According to the Pew Research Center, at least 52 percent of Americans are opposed to the practice while 47 percent are in favor. Arguments against the practice range from the possible existence of alternative research methods in which animal behaviors can be replicated with technology, to the lack of effectiveness and oversight.

But advocates for the use of animals in labs argue they play an invaluable role in scientific research.

Cindy Buckmaster, a biomedical researcher and chairwoman of Americans for Medical Progress based in Houston, said there are currently no good substitutes for animal research in lab settings. Researchers still need to learn a lot about the complexities of living organisms, she said. Technology can’t replicate animal behavior yet, she said, and many experts believe a truly effective and respected alternative probably won’t be developed until 2035.

“What we know is a fraction of what we need to,” she said. “The way we learn about it is through animals.”

Part of the problem, she acknowledged, is that researchers haven’t done the best job of explaining animal research to the public. For one, she said that research topics requiring the use of animals in labs are a result of public outcry for biomedical progress.

“The researchers don’t drive animal-based research,” she said. “That’s driven by the public.”

Earlier this year, California banned the selling of cosmetics that were tested on animals, an update that many animal rights organization saw as a victory toward abolishing the use of research animals in labs. But experts say animal testing for cosmetic use is a practice that has little connection to the research that’s done to advance medicine at places like the VA.

“Our goal is to address issues and real problems that our veteran population faces,” LaRue said.

Black, white and grey

Since the dawn of medicine, animals have been used for medical research. But unlike today, there wasn’t much opposition to the practice in ancient Greece.

A study on the history of animal experiments in biomedical research found it wasn’t until the 1970s and ‘80s when much of the existing opposition got its footing, including a group called PETA, short for People for the Ethical Treatment of Animals, arguably the most vocal among all animal rights organizations.

“The reality is that the majority of animal experiments do not contribute to improving human health,” the group writes on its website, “and the value of the role that animal experimentation plays in most medical advances is questionable.”

Current opponents to the use of animals in research highlight the lack of funding and staffing at federal agencies, including the U.S. Department of Agriculture, responsible for overseeing animal use in labs. And the Animal Legal Defense Fund has argued that the chief federal animal protection law, the Animal Welfare Act, excludes animals like mice that make up majority of the animal testing.

Meanwhile, proponents of the practice tend to focus on medical advancements for humans, including chemotherapy, insulin and the rabies vaccine, that have been made possible because of the use of animal in labs. Most of the Nobel Prizes awarded in physiology or medicine, for example, were given to work that included the use of animal research.

“There’s great value in the animal research,” said LaRue, of the Charleston VA.

Other groups, including the Charleston Animal Society, believe that the issue isn’t so black and white.

Though they see the value in the research, they highly recommend that animals only be used when there aren’t any alternatives and never to benefit research related to cosmetics or household items. They also believe that research organizations should be investing in technological studies that could feed alternative methods and that organizations conducting this type of research need to be more transparent with the public.

We're launching a new weekly newsletter all about health and the health industry in South Carolina. Be the first to know - and it's free.

“We realize that animal testing is a reality,” said Joe Elmore, CEO of the Charleston Animal Society. “This is the gray area and you just try to navigate the gray area as humanely as you possibly can.”

Layers of approval

Most of the nearly 3,000 animals currently being used in South Carolina for active research are mice and rats, according the federal government. More than 400 are dogs and cats.

That research is being conducted across the state — at Clemson University, the University of South Carolina, both VA hospitals, and others.

At Clemson, for example, researchers are regenerating brain tissue in traumatic brain injuries by using adult lab rats. At MUSC, scientists are studying cocaine addiction by testing possible cures on cocaine-addicted rats.

“At this point, there is no way to model all of the complex interactions that occur in living organisms,” MUSC spokesman Tony Ciuffo said in a statement. “Therefore, it continues to be necessary to depend on both human and animal experimentation to prevent and treat diseases.”

Nearby at the VA hospital in Charleston, researchers are currently looking at adult stem cells and how those cells could heal bone fractures in the lower extremities. This led them to the use of the mouse on the catwalk. Other animal research at the VA in Charleston is seeking to address issues associated with sand inhalation as veterans stationed overseas often make contact with sand during deployment.

“With animals models we can get a full picture of what’s happening to the organism in a specific disease or around a specific gene that’s being affected,” LaRue said. “And obviously we can’t do that in a human very easily.”

According to LaRue, getting approval to use animals in research for the VA is extensive. The first layer of approval is conducted at the VA’s central office in Washington D.C., where a veterinarian reviews the proposal and makes sure it is scientifically justified. They also check the number of animals needed to conduct the study “so that we’re using the fewest numbers of animals that we can possibly use,” LaRue said.

Then, the veterinarian takes note of the species proposed for use in the research to ensure that the least sentient species — or the species least likely to feel or perceive things — is used. If the work can be conducted with a mouse, for example, that’s considered preferable to a dog.

If approval is granted in Washington, a local Institutional Animal Care and Use Committee must also sign off on the proposal and provide ongoing inspections of the work.

“And that makes sure that they have the community’s interest in mind as well,” LaRue said. “We justify not only to the scientists and to the researchers, but also to the community.”