By Lisa Myers and Diane Beasley

Rock Center

Rosie and Ken are 30-year-old chimpanzees who've never known a day of freedom. They were born in research labs and have spent almost their entire lives being experimented on by scientists in search of cures for human diseases.

These two chimpanzees have been infected with viruses, darted, and sedated more than 100 times, and put through dozens of sometimes painful procedures. For years, Rosie repeatedly was given a drug that caused her seizures.

Today, these aging chimps are living in large enclosures called primadomes at the Texas Biomedical Research Institute in San Antonio, available to be used for still more experiments. When Rosie and Ken and a dozen other chimps were shipped to the lab, in 2010, after a 10-year hiatus from invasive testing, it provoked a public outcry.

Chimpanzee 'Ken' in his enclosure.

We met Rosie and Ken not long ago, when, after months of negotiation, Texas Biomed gave NBC News unprecedented access to the highly secretive world of primate research.

Dr. Robert Lanford, who has experimented on chimps for 27 years, said he wants the public to see what it's like at his research lab today. "The American people has had the wrong opinion that these animals are in little bitty cages in a dark room with no windows," he said. "I want them to see who we are and how we take care of the animals and why we're doing it."

Dr. John VandeBerg, director of the primate research center, says chimpanzees here are treated "with the utmost of reverence," and have a "high quality of life."

But that quality of life is a matter of intense debate and part of the emotional argument over whether experimenting on chimps is morally and scientifically justified to save human lives. Also at issue: When is enough enough? When do chimps who've given much in the name of science get to retire to the relative freedom of a sanctuary?

One reason chimpanzee research is so controversial is that these amazing creatures share 98 percent of our DNA and have many human traits, including emotions ranging from joy to sadness and fear.

"Remember we're talking about our closest living relatives with brains so sophisticated that they can do a lot of problems on a computer with a touchpad, faster than secondary school students. That's how bright they are," said famed anthropologist and primatologist Jane Goodall in an interview with NBC News.

Dr. Goodall has worked tirelessly for decades to improve the lives of lab chimps and to persuade scientists and the government that this research should be banned.

"All invasive research is torture," Goodall says. "And it's not just the procedures. It's the imprisonment. It's being kept in a small space with no choice. You just are there. You're powerless."

Over the four days our team spent at Texas Biomed, our cameras were required to shoot from a "safe zone," since many of the chimps, like Ken and Rosie, are infected with viruses such as Hepatitis C and HIV. So to get close-ups of the chimps, we built special equipment to attach small cameras to the cages. At first, the chimps tried to remove them — and then, were fascinated by seeing their own reflections in the camera lens.

We saw three different types of housing where the chimps live, enrichment which involves activities to keep them engaged, and their interaction with behaviorists. We observed how the chimpanzees are trained to voluntarily present their own body parts to receive shots. We also were allowed to watch one of Lanford's experiments in which a chimp who'd been infected with the Hepatitis C virus was sedated and then bled. Lanford has been working to find a vaccine for over a decade.

Testing on chimps has saved lives in the past: it helped produce the Hepatitis B vaccine which is now given to children at birth.

But scientists disagree about whether chimps are needed to find a cure for Hepatitis C. Lanford says testing on chimps will save human lives. Chimps are crucial, he says, because they're the only animals that can be infected with the virus. Unlike humans, they don't develop liver disease.

Scientists here also argue that they provide a quality of life for chimpanzees which is just as good as a sanctuary, and that instead of being retired, chimps like Rosie and Ken should live out their days in the labs, in case they are needed for research in the future.

"I think of the chimpanzees in the same way that I think of a library. There are many books in the library that will never be used this year or next year," VandeBerg says. "Many of them might never be used again. But we don't know which ones will be needed tomorrow, next year or the year after."

Anthropologist and primatologist Jane Goodall.

Goodall says that's a terrible idea. "Most of them are just stockpiled. Most of them are not being used. They're just there in case maybe one day we might want to use them again," she said. "I definitely think at a certain point, they deserve to be freed from this kind of life of servitude."

Whether a chimp gets to retire is entirely up to the labs and the government. There is no ethical standard or uniform criteria.

According to Goodall, "the tragedy is that some of the chimps in the labs know nothing else. They have never tasted any kind of freedom in their lives. Freedom to choose, freedom to go where they want."

To see what life looks like for lab chimps lucky enough to be deemed no longer needed for research, we spent two days at the National Chimpanzee Sanctuary in Shreveport, Louisiana. It's aptly known as "Chimp Haven."

In the back woods of Louisiana, for the first time in most of their lives, the chimps can walk on grass, swing in the trees ... and forage in the forest.

Dr. Linda Brent founded Chimp Haven, after spending 16 years as a behaviorist at Texas Biomed. "Everything we do here, from the way the facility was built to the things we give to the chimpanzees and the way we manage the facility, every decision we make is for the welfare of the chimpanzees," she says.

Additional Resources: For more information on the National Chimpanzee Sanctuary, Chimp Haven, click here. For more information on the Texas Biomedical Research Institute, click here. For more information on Jane Goodall’s work and the Jane Goodall Institute, click here. To learn about a group of lab chimpanzees that Goodall helped get placed in the Fauna sanctuary outside of Montreal, Canada, click here. To learn more about the Great Ape Protection Act that Goodall is working to pass, click here.

