The rat I loved | Translation

The rat I loved | Translation


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Translated by MC Editorial

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[Daniel Alarcón]: A warning: this episode contains descriptions of animal testing. This is Radio Ambulante, from NPR. I’m Daniel Alarcón. 

[Manuel Rojas]: It’s just that experimental animals have a . . . miserable life. . . 

[Daniel]: This is Manuel Rojas, Colombian. Neuroscientist and expert in physiology.

[Manuel]: I have always said that, for me, the happiest moment of an experiment is the day when I have to sacrifice, euthanize, the animals when the experiment is over.

[Daniel]: Manuel is 61 years old, and he has searched for answers about consciousness, perception and sleep for over three decades. How does our brain work when we sleep? Which neurons are active or inactive at that moment? What happens to them in states of deep unconsciousness, such as when someone is in a coma, under general anesthesia, or under the influence of some powerful drug?

To answer that and other questions, Manuel has needed to experiment on living brains, and he cannot do it with humans, of course. That is why, like many scientists around the world, he uses laboratory rats.

[Manuel]: So there are lines of mice, lines of rats that are genetically controlled, hundreds and thousands of animals that are practically identical.

[Daniel]: Animals that are born and die to generate scientific knowledge.

[Manuel]: This allows me to carry out an experiment with a lot of statistical weight, and in which I introduce only one variable, which is my experimental variable.

[Daniel]: It’s a job of digging and digging into the mystery of their consciousness. After inducing the rats into sleep or anesthetic states, he measures their reactions to different stimuli with electrodes in their brains. And, after a while, when the experiments are over, he has to sacrifice them.

Manuel has done it a hundred times. And that’s what science has always had to do. In Ancient Greece, the pioneers of anatomical study sacrificed monkeys, goats and pigs to observe, understand and classify their organs. Galen, one of the great doctors in history, cut open different animals to understand how the lungs or spinal cord work. This is how a large part of modern medicine was born, and this is how we have managed to understand how our body works—our life.

[Manuel]: The use of animal models allowed science to clarify a great deal about the functions of physiology, how organisms work,  also the human species. And it allowed, and still allows, work in the quest for treatments, prophylaxis, disease prevention. Otherwise, it would not have been possible to come as far as we have come.

[Daniel]: But the fact that animal experimentation is key to the advancement of science does not mean that it is always so easy for all scientists to do it. They may wonder, sometimes, what those animals feel.

[Manuel]: Now, do I think about “Am I doing something that causes pain, that causes suffering to the animal?” Of course I do.

[Daniel]: However, it is an unavoidable part of his profession as a scientist.

[Manuel]: I just have to do it . . . 

[Daniel]: Or else he couldn’t continue studying consciousness.

But almost twenty years ago, what should never happen to a scientist happened to him: he became attached to an “experimental object,” to a lab rat. A rat that had even been given a name: Manuela. A rat that, like all the others, he would eventually have to sacrifice.

This is the story of Manuel and Manuela. A scientific love story.

We’ll be back after a short break.

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[Daniel]: Juan Sebastián Salazar Piedrahita and Nicolás Alonso produced this story. Juan Sebastián continues the story.

[Juan Sebastián Salazar Piedrahíta]: To understand a love story, you first have to understand its protagonists: where they come from, who they were in the past. Before becoming a neuroscientist, Manuel grew up in a poor family in Bogotá. It was the sixties. He, his brother, his parents, his grandparents, several cousins and uncles, lived in an old house that belonged to his grandmother, with other people who rented rooms.

There were a lot of people and lots of animals. If one thing is always present in Manuel’s childhood memories, it’s animals. Dogs, cats, chickens. And pigeons, lots of pigeons, which used to hide under the eaves of the house.

[Manuel]: The love and affection that my whole family always felt for animals was very obvious. It was a very close relationship; all the pets were members of the family, you know?

[Juan Sebastián]: That would influence his decision to study Veterinary Medicine, although what Manuel really wanted was to be a doctor. Especially since the time he was a teenager, when his grandmother started getting old and sick.

[Manuel]: I saw her when she was complaining. Sometimes she had vomiting and pain. And I remember telling her, “Grandma, I’m going to be a doctor so I can cure you.”

[Juan Sebastián]: He wanted to study Medicine at the National University of Colombia, one of the best universities in the country, but he didn’t get the score needed. So he decided on Veterinary Medicine, a career in which he could also learn about living organisms in order to heal. It was 1979, and little by little, he became enthusiastic about the complexity of his courses:  learning to decipher the anatomy, the organs, and understand the ailments of all kinds of animal species. Dogs, cats, cattle, horses and birds . . . that first year of college, he also began to protect them.

[Manuel]: My work as an activist at that time was mainly for stray animals: dogs, and horses used for carts, which were a problem in Bogotá.

[Juan Sebastián]: Horses carrying heavy loads around the city, pulling a cart. Many lived in terrible conditions, so Manuel used to write to the District Government demanding regulations. He also asked for reports of measures being taken to control the population of stray dogs, which were often euthanized. He proposed sterilization campaigns, educational campaigns . . . and he also did some interventions to help them on the streets.

[Manuel]: If an injured or sick animal was found on the street, try to cure it or treat it and have it adopted. Or if there was an animal, well, injured, dying, suffering . . . well, sacrifice it right then and there . . .

[Juan Sebastián]: Manuel asked his more advanced university classmates to teach him how to give intravenous injections. And he went to chemical stores looking for chloroform to use as an anesthetic. He carried all that in his briefcase. If he found a dying animal, he anesthetized it and accompanied it until it died of natural causes.

But if he saw that they were still suffering, he had to give them the lethal injection.

[Manuel]: Despite the fact that, yes, it was relieving the pain and suffering of an animal, for the one who did it, it was not pleasant at all. I always felt that I was killing.

[Juan Sebastián]: Manuel defended the rights of animals, but he could only do so outside the university . . . inside, it was simply not possible. He understood this clearly during one of his physiology classes, the branch of biology that studies the physical and chemical functions of living organisms.

Let’s imagine Manuel, young and an activist, in a room, sitting at a desk, with the board in front of him. The teacher is explaining the functions of the cerebellum, the part that allows us to control balance and, in the case of birds, the ability to navigate. Then, to everyone’s surprise, he brings out a pigeon that he has brought to class. Without much preamble, he jabs a needle into its brain, injures the cerebellum, and sends it flying.

The pigeon crashes into the walls, over and over again, as the students watch, occasionally ducking to avoid it. The animal does not have a compass. It does not know where to go, and it is unable to stop.

Scenes like this were common in the teaching of medical sciences in those years, and of course, they were disturbing to Manuel.

[Manuel]: I didn’t feel well. I said but, but, but it is absurd. I mean, like, how can they do this to an animal that is alive, without anesthesia or anything?

[Juan Sebastián]: That went against what he had been taught as a child.

[Manuel]: I was raised with the awareness that animals feel. If I had my dog or my cat, they were always telling me no, don’t do this to him because it hurts.

[Juan Sebastián]: At that time, in the early 1980s, Colombian laws defined animals only as “self-moving,” that is, as movable property. Nothing more than that. In the university, there was no way to apply conscientious objection. To raise your hand and say, “Hey, professor, I can’t do that; it makes me feel bad.” Manuel wanted to be a veterinarian and he was the first in his immediate family to go to college . . . If the professor of such an important institution did things like that, well, they had to be accepted. Although they were uncomfortable.

[Manuel Rojas]: Now imagine. This generates . . . a confrontation with your own ideas, right? Because you are a student, you don’t have the choice between doing an experiment on an animal or refusing. You either do it or you leave college.

[Juan Sebastián]: In other classes, such as toxicology, they were asked to do experiments on stray dogs. They gave them poisons to observe how these affected their muscles, or they operated on them to remove organs while they were still alive . . . 

[Manuel]: Those were the kinds of experiments that were going on at the time. This was obviously evolving, and it became more and more, let’s say,  more humane. All that, fortunately, has changed drastically.

[Juan Sebastián]: In Colombia, those practices began to change in 1989, when the National Statute for the Protection of Animals was signed, prohibiting experiments on live animals in classes or university lectures.

It also established several norms that the UN and the Council of the European Communities had been suggesting for laboratory experiments, and that the United States government had already established as law in 1986: using animals only when there is no other way to attain knowledge; if the tests show new results or advances against diseases; with compassionate treatment, and always using anesthetics in the experiments, among other things.

These and other standards are now basic in laboratories worldwide.

But that is recent history. As we said, for centuries, science did not have too many objections to the pain of animals. In reality, animals were not even believed to have the capacity to suffer.

[Manuel]: In the early days of science, that’s almost an extrapolation from religion, where religion considered that only men, and at first only white men, had souls. Likewise, in science it was considered that the only . . . sentient beings were humans.

[Juan Sebastián]: Animals were also not believed to have emotions, but the bodies of some species could provide answers about how ours works. And human beings do not resemble a slug or a crocodile, but rather other mammals, such as chimpanzees, which is why a lot of experimentation was carried out on them for decades.

Manuel told me that, fortunately, those experiments are very scarce in the world today, as much more is known about the sensitivity of these kinds of animals.

By 2017, in the European Union, about 61 percent of the animals used in experiments were mice, 12 were rats, 13 were fish, 6 were birds, and only 0.3 percent were other mammals such as dogs, cats or primates.

It also has to do with something practical. It is easier to manage hundreds of genetically identical rats than to keep a building full of chimpanzees. In any case, animals are still essential for understanding biological processes, testing new drugs and therapies, and being able to advance toward the cure of diseases.

[Manuel]: As my grandmother would say, this is where Christ begins to suffer and the mother begins to struggle . . . Unfortunately, we humans have not yet found a way of not depending on the use of animals for experimentation.

[Juan Sebastián]: Louis Pasteur developed the rabies vaccine after injecting the virus into dogs and rabbits. Organ transplant pioneer Alexis Carrel performed his first operations on cats and dogs. The Rh factor, the protein that allows us to know our blood group and therefore receive transfusions, is named after the Rhesus Monkeys —Rh-esus—, the species that was experimented on to type human blood. Diabetes, cancer, AIDS; heart, respiratory or brain diseases. None of these could have been treatable, or at least understandable, without the use of animals.

According to the University of Navarra, until 2006, 76% of the Nobel Prize winners in Medicine had made discoveries by experimenting on them.

The semesters went by, and as a veterinary student Manuel got used to the type of practices he was asked to do.

[Manuel]: I think that you lose sensitivity; anyway, you always question yourself, right? Ahh, it’s hard to have to do this, but, well, you have to do it.

[Juan Sebastián]: Little by little, his interest in healing animals gave way to the scientific method—hypotheses, experiments . . . There was something in that life, the life of a researcher, that began to appeal to him strongly. Perhaps the first moment he felt it clearly was during his seventh semester, when the Nevado del Ruiz volcano erupted, spreading its ashes over Colombia. Manuel began collecting samples from different regions to analyze how they were affecting the cattle that ate contaminated grass. They were simple studies, but every step was exciting for him.

[Manuel]: It is an emotional thing. It is very gratifying to see that you do experiments, that you do things that give you results, they give you numbers, they give you things that make you say, “Wow, impressive… how…  how did I get to this.

[Juan Sebastián]: But doing research in Colombia is not that easy, and even less so back then. When he graduated in 1988, he had no money for a graduate degree.

[Manuel]: You simply graduated and had to survive. Let’s see what I can do.

[Juan Sebastián]: What he did was take a job as a veterinary inspector. He had to be up at 2 a.m. at a slaughterhouse, supervising that the chickens were killed more or less hygienically.

[Manuel]: An absurd thing. I mean, I’m not healing animals, I’m not saving animals, I’m not doing research or anything like that. But it was the only job I could get.

[Juan Sebastián]: During those years, he also had an office, Veterinaria MR Manuel Rojas, where he healed animals and gave work to recently graduated colleagues. He worked there on weekends with his girlfriend, a veterinary student who years later would become his wife and his research partner. He would have that office for 12 years, but by then his desire to be a scientist was stronger than anything else. So when a university professor invited him to join his research group, he did not hesitate to accept, even if he was not paid anything.

There was talk in Colombia of a new form of crime, which used a drug —burundanga (scopolamine) or “zombie drug”—that annulled the will of its victims, leaving them in semi-conscious states. Then they were robbed or abused. There were terrifying cases reported in the media.

The team wanted to understand its effects on the nervous system, and for that they would test it on mice. They were looking for ways to figure out what dose of the drug caused effects on mice similar to the effects suffered by humans. That was the first key step before performing more complex studies. For Manuel, those experiments—his first with mice—were the confirmation of a path. Two years later, he got a loan to go to Spain and do a master’s degree in neuroscience, with a friend from the same team.

[Manuel]: It was like a switch, a leap there… which led us fully into the path of neuroscience, you know?

[Juan Sebastián]: It was 1997 when he entered the International University of Andalusia. There he was dazzled by the study of the brain and consciousness. He did more experiments on mice, investigated how neurons communicate with each other, and became interested in sleep states . . . the topics that would lead him, years later, to meet Manuela, the rat that would be so different from all the others.

With his master’s degree, Manuel worked as a professor at a university in Colombia, and then traveled to Los Angeles, in the United States, to work at the University of California, at one of the most important sleep research laboratories in the world. There, he would investigate states of unconsciousness and, specifically, narcolepsy, a disorder that generates extreme sleepiness and sudden fits of sleep; those who suffer from it can be “knocked out” suddenly, anywhere.

At that time, in the year 2000, researchers were trying to understand how it worked, and so they were experimenting with animals used to sleeping many hours a day: cats.

[Manuel]: I need them to sleep while I experiment on them and it’s easy to train them to be sleeping even though I’m doing things to them.

[Juan Sebastián]: What they did —and outside of the scientific realm, this can feel shocking— was to anesthetize them and open a hole measuring a few millimeters in their skull, to place electrodes in their brain. Manuel, who had experience as a surgeon, took care of that. Then they were given a drug to simulate narcolepsy and the scientists began to measure the activity of different parts of the brain.

With this approach, they made lots of progress in the three years that Manuel was at the lab. They found, for example, that cats in that state lost the capacity to move due to a decrease in neurotransmitters called orexins. Narcolepsy still has no cure, but different findings from researchers around the world have made it possible to treat it today with drugs and lifestyle changes.

But going back to Manuel . . . He was excited about the discoveries they were making, but he couldn’t stand experimenting with cats any more.

[Manuel]: This was something that really brought me to a pretty high stress level. Working with cats is very complicated because cats are terribly affectionate animals . . . just as they are independent, they also show you . . . something that we can perhaps describe as affection, or something like that.

[Juan Sebastián]: Until one day the lab’s principal researcher left, and the sleep studies came to a halt.

[Manuel]: And I’m like . . . And what? Me here? What do I do?

[Juan Sebastián]: The news took him by surprise. There was no plan B or C, nor any desire to return to Colombia. So he started applying to universities in the United States: Los Angeles, New York, San Francisco, Chicago . . . anywhere. Until he got a response from Washington State University, in the town of Pullman, near Canada. He was offered a job working as a researcher in a sleep laboratory, so he accepted without hesitation.

[Manuel]: I had no idea that university existed, much less that there was a tiny town in the middle of nowhere.

[Juan Sebastián]: The lab needed someone like Manuel, who had experience in surgery, and who knew a lot about anesthesia and states of consciousness. He packed his things and traveled by car over 18 hours from sunny, cosmopolitan Los Angeles to passive, white Pullman, in the state of Washington. A very cold place, with moose around.

He arrived at an apartment that was part of a residential complex on campus. His wife would come to live with him half a year later, and she too would work at the university sleep lab.

But for the moment, he was alone, surrounded by snow.

In the lab at Washington State University, they wanted to explore the mechanisms of sleep in the brain, and for that they had specialized scientists, state-of-the-art equipment, and rats. Lots of rats. Manuel explained to me that his interest in the study of sleep was born from another, deeper interest, which has guided his entire career:

[Manuel]: What is consciousness, what is it, how does it work? And obviously, if we manage to know what it is and how it works, we could eventually know what species have consciousness and which species do not have consciousness.

[Juan Sebastián]: But that is a question for which there are very few answers. Manuel told me that, even today, neuroscientists do not know exactly the place or places in the brain where consciousness is generated, and they have not even achieved a clear definition of exactly what that voice inside our head is, that ignition switch of our mind. But what we do know is when it’s not on—that is, when we’re dreaming, under general anesthesia, in a coma, or well . . . when we’re dead.

[Manuel]: But there is no way: How can I perform an experiment where I try to answer the question of what consciousness is or where consciousness is? Instead, what I can do is an experiment where I know that I have the animal in a state of unconsciousness, and I can posit experimental questions and answer them by designing experiments to find out which areas of the brain are working, which ones have been turned off, which ones have been reactivated.

[Juan Sebastián]: Manuel told me about various medical advances that would be possible if we understood consciousness. For example, understanding the state of coma, about which we know little. We could clearly assessing whether someone will ever be conscious again and what we could do to speed up that process. Or we could better manage general anesthesia states in order to prevent patients from waking up during operations—or worse, not coming back.

And one of the first steps to understand it, according to Manuel, is to study the most common state of unconsciousness in all animals: sleep.

[Manuel]: All animal species—all of them, including the human species—spend at least a third of their lifetime sleeping. If you are sixty years old, you have been sleeping for twenty years. So it is very important.

[Juan Sebastián]: At the lab, they studied rats in deep sleep, wakefulness and anesthesia states, and using electrodes, they measured their brain activity against different stimuli. These were cutting-edge experiments, and in order to conduct them, they even had to develop their own software. They also had to train the rats to stay still for hours, in a kind of straitjacket.

[Manuel]: Starting with five seconds, ten seconds, 15 seconds, and so on, until we had rats that perfectly tolerated being still for two hours; they slept and woke up and slept and woke up.

[Juan Sebastián]: They were rats that arrived two months after birth from other labs, where thousands and thousands like them are produced. An industry that works by mail orders, where scientists can order what they need for their experiments: hairless rats, rats with mutated genes, rats designed to develop diseases such as cancer, Alzheimer’s, Parkinson’s . . . or normal rats of the same age, species and weight, identical rats.

[Manuel]: They arrived at the lab, where they were received and distributed, two rats per box, in a space that we humans assume is sufficient living space for them . . . Who knows if . . . if they agree, right?

[Juan Sebastián]: A space somewhat larger than a shoe box, where they received their food and drink. Then they went to another space, where they were trained for a while before going back to the box. Once prepared, they were anesthetized and surgery was performed on their skulls, very similar to what Manuel had done with cats. They opened a hole of about three millimeters and placed a handful of electrodes in to measure the activity of their brains while they slept.

But there was a big problem: many rats did not resist the operation. Since Manuel had a lot of experience in this type of procedure, one of his missions was to ensure that no more rats died.

[Manuel]: What I did was establish a new protocol, with another type of anesthetic, with another type of analgesic, antibiotics. And that was really a hit.

[Juan Sebastián]: Manuel began to operate on the rats for all lines of research in the laboratory. He was at it for about six months, while new litters were trained to move on to the experimentation phase. Once operated and used to sleeping for long periods, the tests began with different stimuli: lights, sounds, touch.

[Manuel]: And so up there in the brain, I’m recording what happens in those neurons at certain times, when the rat is asleep, when it’s awake, when it’s in a certain state of sleep.

[Juan Sebastián]: And if all this sounds harsh or unpleasant, I can assure you that, directly or indirectly, we have all benefited from the suffering of some lab rat. Science is like that. And that’s how it’s always been.

After spending six months as a lab surgeon, Manuel had his group of collaborators established and was ready to design his own experiments. And he would have his own rats, too.

One day, his first litter arrived. And there she was.

[Manuel]: What I have always said is that Manuela was my first experimental rat from the first group that I had to operate on for my own ends.

[Juan Sebastián]: It was the first rat whose fate depended entirely on him, and she had arrived at the lab as a two-month-old, like any other rat, mail-ordered. At first, she was like all the others: white, whiskered, and trained to sleep for hours while he searched for answers in her tiny brain. Manuel wanted to study the neurons of the somatosensory area, the area in charge of planning and executing movements while we sleep or are awake.

For him, who had been suffering stress from experimenting with cats, it was much more comfortable to work with a rat, which was apparently less affectionate.

[Manuel]: I mean, I couldn’t even think that something special was going to happen with Manuela, or something like that, right? She was just the rat on duty.

[Juan Sebastián]: One among hundreds that had passed through his hands.

[Manuel]: I didn’t have the luxury of becoming attached to experimental animals. Because, well, that would drive anyone crazy. That’s not allowed.

[Juan Sebastián]: He felt comfortable, and the animal showed very good records in all his experiments. So the months passed, and one day, one of the lab technicians named her in honor of the researcher who spent so much time with her, Manuel. She was the only rat with a name.

[Manuel]: Animals have always been identified with a number, but in this case, as it was a rat that had been working for so long, she was already known: Who is going to experiment today? Ah, there is an experiment with Manuela. Done . . . so, as if she had an identity . . . 

[Juan Sebastián]: Almost a year went by. Manuel did experiments and kept his records. Every day, a similar routine: say hello, check that the rats were doing well, do some surgery, put their little jackets on them, stimulate, observe and, from time to time, find a new clue.

But one morning, things changed. He went into the lab, like any other day, organized his desk, checked his tasks, and toured the animal facility, where the rats lived in their boxes. He had to work with Manuela. He attached the electrodes leading from her brain to the machine and began to measure. Manuela was supposed to fall asleep, peacefully. But that didn’t happen. Suddenly she jerked her head.

[Manuel]: At some point, she exerted some force and, well, the plug was completely released . . . 

[Juan Sebastián]: The plug with the electrodes. Over time, it often happened that they came loose, due to the body’s own defenses.

But it was not common for it to come off completely.

[Manuel]: It very rarely happens as it happened to Manuela, that the implant fell out and the skull, the bone . . . 

[Juan Sebastián]: Manuel froze. Manuela had part of her skull exposed, and that meant only one thing: He would have to sacrifice her. He knew it perfectly.

[Manuel]: The protocol is euthanasia, immediately, because, well, first of all, the animal will not be usable for another experiment because it is forbidden to perform double surgery on an animal. Most likely, the animal is in pain, and that’s when you adopt what is called the end point.

[Juan Sebastián]: But, for some reason, with Manuela he didn’t want to do it.

[Manuel]: No, I don’t know . . . what happened to me at that moment, I don’t know.

[Juan Sebastián]: He didn’t want to sacrifice Manuela, even though he knew it was what he had to do. Also, it was something he had done since his days as an activist: euthanize to avoid suffering. But he kept hesitating . . . 

[Manuel]: So the fact that it was Manuela and not any other rat, and the fact that the head of the lab was not there that day . . . 

[Juan Sebastián]: Made him consider another possibility . . . Next to him were his surgical and anesthetic tools. So he got an idea:

[Manuel]: Hey, why don’t we put her under anesthesia and, well, suture her up and see what happens to her? . . .

[Juan Sebastián]: That’s what Manuel thought . . . that he could anesthetize her, sew up her little head and prevent her from continuing to suffer, but without having to kill her.

Although for that, he had to break the rules.

Manuel did not report the situation to any of his superiors. He just anesthetized Manuela, prepared his instruments, and sewed her up with a tiny needle. The surgery was a success and lasted a few minutes. Manuela survived and he left her in her little box, as if nothing had happened.

[Manuel]: It was something . . . spontaneous. When I sutured her, I didn’t even think, “Well, what am I going to do with her later?”

[Juan Sebastián]: He just did it.

[Manuel]: Of course I knew that I was going against the protocols, that the rat could no longer continue as an experimental subject. And I don’t know, no, the truth is, I don’t know, I think it was something emotional, right?

[Juan Sebastián]: For the first time, the scientist was acting irrationally.

A few hours passed and the place began to fill up with researchers. Until the lab manager, who had arrived, called Manuel into his office. He entered quietly. The head of the lab said:

[Manuel]: The lab manager tells me that one of the rats lost the connector and you did not sacrifice it.

[Juan Sebastián]: Manuel told him that it was true.

[Manuel]: Then she asks me, “So . . . what is going to happen to that rat?” And I told her, “Well . . . I see several options.”

[Juan Sebastián]: The first was that they could use her in an acute experiment, that is, one in which she was anesthetized, measured, and died before waking up. But what he was saying did not make much sense, because hours before, he had operated on her to prevent her from dying.

Until he dared to state the second option:

[Manuel]: And . . . the other . . . is that I take her . . . take her out of the lab . . . and I’m going to keep her as a pet.

[Juan Sebastián]: The lab manager looked at him.

[Manuel]: You know that this cannot be done. It is not in the protocols. No experimental animal can be kept as a pet.

[Juan Sebastián]: There was no other option: he had to put her down immediately. But that answer started a discussion at the lab.

[Manuel]: Everyone had an opinion, right? And suggestions . . . 

[Juan Sebastián]: Surprisingly, his colleagues supported him. And his wife too.

[Manuel]: Sure, why not let him take it away and keep it as a pet? The rat has already worked here for many months.

[Juan Sebastián]: The lab manager kept telling them no, that it was impossible, but Manuel and some of the team kept insisting. Suddenly everyone believed that Manuela deserved to retire. Until after a few minutes, the manager ended up giving in to the pressure. He looked at Manuel and said:

[Manuel]: As if to say, “I’m closing my eyes. I have no idea, I don’t know what happened to that rat. The only thing is that I don’t want to see the rat here tomorrow.”

[Juan Sebastián]: It was not a small favor. He was skipping a university protocol, something that could bring sanctions to the lab.

[Manuel]: And so that’s how things ended. I simply borrowed a box and brought her back to my apartment. And that’s when Manuela got adopted.

[Juan Sebastián]: It was an old-fashioned “adoption.” No need to sign papers with commitments about the care of the animal; far from it. He simply put Manuela in a box, and took her home at the end of the day.

He had adopted a lab rat and had no idea what their life together would be like. But for some reason, he felt happy.

[Daniel]: We’ll be back after a break.

[Dynamic Mid-Roll]

[Daniel]: We’re back with Radio Ambulante. I’m Daniel Alarcón.

Before the break, we heard how Colombian researcher Manuel Rojas was unable to put down one of his lab rats at Washington State University and, on an impulse, decided to adopt it.

Juan Sebastián Salazar Piedrahíta picks up the story.

[Juan Sebastián]: Manuel walked to the apartment complex with the box. He had taken an animal from the lab and, as if that were not enough, it was strictly forbidden to have pets in the university residences.

[Manuel]: We can say it was an option that I put out there without foreseeing anything at all, right? . . . how can I keep it or what is going to happen or . . . no, no idea.

[Juan Sebastián]: But there he was, with Manuela in his arms. When he arrived at the apartment, he opened the box and his new pet ran out. The first thing she did, once she was free, was to hide quietly in a corner, between two walls.

And there she stayed, looking at her new environment.

[Manuel]: That is the normal reaction of rodents. Because they feel protected, because she has at least three shields of protection.

[Juan Sebastián]: The two walls and the ceiling, as in her little box. Manuel and his wife talked about how to give the new member of the family a good life. The first thing was to find her a more comfortable place to live.

[Manuel]: I was happy, and in fact, like a little boy, I began to build her what I later told everyone: “I built a penthouse for Manuela.”

[Juan Sebastián]: With exercise wheels, stairs, mazes. They had fun designing the house for her . . . 

[Manuel]: Where is it better to put this, and this little wheel here. With the idea of making her life with us as entertaining and as fun as possible, right?

[Juan Sebastián]: Little by little, Manuela was daring to explore her penthouse. She walked around and smelled, gaining confidence in the objects that surrounded her, so different from those of the place where they had experimented with her. Despite the scars on her head, she was still a normal rat . . . 

[Manuel]: She learned to handle the little games, and go up and down, and go to the second, to the third floor, and come down . . . 

[Juan Sebastián]: She even toured the apartment.

[Manuel]: We took her out every day and let her loose, and she started exploring. Often, we did not know where she was. Until we saw her somewhere: “oh, look, there she is . . . she’s hanging there, she’s climbing up there…” 

[Juan Sebastián]: Manuel played with her when he came home from the lab. It was as if, once again, he was in his grandmother’s old house with his dogs and cats . . . when animals were just company.

When he had the chance, he bought her a gift.

[Manuel]: A different color ball and, oh, let’s get it and see if she likes it, and always . . . trying to expose her to different shapes or objects to see if they caused her any curiosity. Sometimes they did, sometimes they didn’t.

[Juan Sebastián]: In a certain way, they were stimuli like the ones he had applied to her before, but now Manuela could decide if she wanted to interact with them, without a straitjacket. It’s not that Manuel began to experiment with Manuela at home, but he did observe her behavior and asked himself questions:

[Manuel]: We asked ourselves, could it be that Manuela understands that . . . that her name is Manuela?

[Juan Sebastián]: Sometimes he suspected she did, because when he called her, she would look back, wiggling her whiskers. Then more questions came up: Is she happy? Could she be aware of the change from one space to another?

He even felt that Manuela was affectionate towards him.

[Manuel]: For example, you give her kisses and you think the rat feels the same. That she is also giving kisses to you when she moves her nose and her whiskers.

[Juan Sebastián]: And she was even different from the other rats.

[Manuel]: And well, we thought her face was very pretty. Well, it must be the same as all rats, but we thought it was very pretty.

[Juan Sebastián]: At the university, Manuel used to visit another researcher who worked near his lab and carried out fascinating studies. Today he is known as “the father of affective neuroscience,” although in those years he was known by another and more humorous nickname. Somewhat jokingly, neuroscientist Jaak Panksepp was called “the rat tickler.”

And he had earned it. A few years earlier, he was studying the reactions of rats to different stimuli. Some he didn’t feed, others he fed sugar. Some lived alone, others accompanied. One day he began to tickle their bellies and he realized that if he stopped doing it, they would nip his fingers a little, without hurting him, as if asking him to continue.

So one of his students went looking for a device to listen to the ultrasounds made by bats, which the human ear cannot hear. With this, such sounds could be lowered to audible frequencies. They started tickling the rats, and this is what they heard:

[Rats]: Hee-hee-hee-hee.

[Juan Sebastián]: In a BBC documentary, while playing with two rats in a glass cubicle, Panksepp says the sound could be their laughter.

[Jaak Panksepp]: As we have listened to animals playing, we have heard what appeared to be a sound of laughter.

[Juan Sebastián]: The rats played and followed his hands wherever he moved them.

[Jaak Panksepp]: And when we tested these animals to ask whether they were enjoying this kind of activity, the unambiguous answer was yes.

[Juan Sebastián]: And when they tested them with electrodes on their brains, the signs were clear: The rats were enjoying themselves; that was evident in the activity in the neuron areas that are related to pleasure and joy. Over time, Panksepp also showed that the rats they played with the most became more socially sophisticated. The more they played, the less they fought and the more they mated. They were happy.

Manuel went to his lab and saw dozens of rats divided into panels: on one side the happy rats and on the other the sad ones. And he was struck by this.

[Manuel]: For me, Jack Panksepp’s discoveries were key to my way of seeing experimental animals, of seeing other animal species because… he was confirming scientifically that this could happen, that they could develop emotions.

[Juan Sebastián]: Panksepp wanted to understand what exactly emotions are, where in the brain they are generated. And for that he did studies on dogs, chicks, guinea pigs and rats. He would separate a puppy from its mother and analyze what responses were generated in its brain. Or he stimulated different reactions, like joy or crying, and he observed whether that affected their behavior—whether they became lonelier, if they didn’t want to mate anymore. If their emotions changed.

So he managed to demonstrate that humans and other mammals get excited through the same neurochemical and anatomical processes. These happen in an area in the center of the brain, in the subcortical structure, which we all have inherited from a common ancestor millions of years ago.

Jaak Panksepp died in 2017, and Manuel had been in touch with him for several years. In his talks he always said that if we can understand the emotions of rats and other mammals, we will understand our own. He made a lot of progress on that. He managed to define seven primary emotional systems that would be in the brain of all mammals: anger, fear, sexual desire, caring for another, panic, exploration, and play, which, when stimulated, produce in us anger, anxiety, excitement, nurturing instinct, sadness, expectations or joy. And so, experimenting on lab animals, he explored new medical treatments for depression.

In his apartment, Manuel also wondered about Manuela’s emotions, but he kept his investigative spirit at bay. If he had taken her from the lab, it was so that she would be his companion, not to resolve doubts about her emotions or her way of expressing affection. After a while, she was part of the routine at home.

[Manuel]: She became part of the family. We shared and . . . we played and laughed and that was it, right? Like a puppy or a kitten, or like a little brother, right? You get up and . . . like everyone in the family, you always say hello, right? So, say hello to Manuela: What’s going on, Manuela? What are you doing?

[Juan Sebastián]: What’s up, Manuela? Everything’s fine? Are you hungry? Do you want me to tickle you? Before going to work in the morning, they left food and water in the cage and said goodbye to her. Then Manuel went off to the lab and continued his experiments with the others, observing stimuli in rats that had no name, only a number to identify them.

And somehow, he managed to keep those two worlds apart.

[Manuel]: Because I was very aware that I was experimenting with animals and . . . well, these were simply the experimental animals. This is Manuela. Manuela managed to save herself from that . . . and she is living with us, cool, but the others, unfortunately, are at work.

[Juan Sebastián]: The others, for better or worse, were still essential to understanding the mysteries of sleep. Manuel told me that one of the great discoveries in which he participated in his career happened around that time, and it had to do with a group of neurons in the somatosensory area, the area of the brain that regulates the sense of touch, that is, our perception of the size and shape of things, of pain and temperature. The experiments showed that these neurons are activated differently when the individual is asleep or awake. So far, a bit obvious . . . But that was not all.

[Manuel]: The most interesting thing about this is that we found that often there are neurons that, although the individual is awake, work as if they were asleep . . . 

[Juan Sebastián]: And others that do the opposite: they seem to be asleep when the individual is awake. Manuel explained to me that this finding could give clues about, for example, why we fail to do motor tasks for which we have received a lot of training. A factory worker, or the person who operates a crane, used to doing the same movement over and over again, day after day, mechanically, suddenly fails. They press a button or make a wrong movement, and disaster strikes.

What happened at that moment in their brains?

[Manuel]: One possible answer is that part of the neurons that were in charge of motor control at that moment —that were in charge of the response the person had to have, some of those had . . . for some reason, entered a sleep state, and that is why errors may happen.

[Juan Sebastián]: Manuel was fascinated by that kind of discoveries: for every clue about how the brain works, another ten questions popped up. At the end of the day, he would come home and, if he could, he would bring a snack for Manuela, the lucky one.

[Manuel]: We started giving her, just as you do with pets, right? A small piece of cheese, a sweet treat, a bite of whatever . . . 

[Juan Sebastián]: Since she was free, sometimes she got lost and they had to look for her all over the apartment, calling her name . . . When they went to bed, they put her in the penthouse, closed the door and said good night, little treasure, may the little angels take care of you, may the rat lord grant you sweet dreams.

Manuela came to Manuel’s house when she was about a year old and lived with them for another two years. And, well, she . . . she lived happily, or at least that’s what Manuel thinks.

[Manuel Rojas]: It becomes like a symbol of . . . Oh, that’s cool. At least this rat is not suffering what all lab animals suffer, but is having a good time, you know?

[Juan Sebastián]: From time to time, they had to hide her, because the administration sent its employees to do maintenance. He left the penthouse in the closet and turned on the radio to prevent them from hearing any strange noises . . . 

It was a very quiet life, beyond those concealment maneuvers. Manuela never ran away, she never bit anyone, she didn’t damage any furniture or cable . . . except that as time went on, she got very fat.

[Manuel]: She began to change. First she became very obese. Well . . . obviously that’s the fault of . . . the food we were giving her, all those treats and snacks and everything, so . . . very, very, very obese. She was a ball of fat.

[Juan Sebastián]: She lived like this until she turned two years old, then suddenly, she began to lose weight rapidly.

[Manuel]: And I began to notice that she had tumors distributed in some parts of her body, so, well, that showed that most likely she was developing cancer.

[Juan Sebastián]: In just a couple of months, Manuela became much less active. She spent all day quietly in her penthouse, in a corner. She no longer left her cage and she did not respond to calls, either. It was all the same to her if they gave her peanut butter, her favorite food.

Once again, Manuel had to face the same dilemma he’d faced in the lab the day Manuela ripped off the electrodes.

But he still didn’t feel he could do it.

[Manuel]: Well, I didn’t think about the option of sacrificing her, but what I really said was, well . . . I’m going to keep her until she dies . . . let’s say a natural death.

[Juan Sebastián]: The days passed, and Manuela continued to get worse. Manuel got up, and the first thing they did was go to the penthouse to see if she was any better, if she had eaten anything, if she had explored her space . . . but no.

Two weeks went by like this.

[Manuel]: She didn’t move, she was quiet there. I put water, food, up to her mouth, and she ate a little bit, she drank a little bit . . . 

[Juan Sebastián]: When one of the tumors ulcerated, Manuel began to clean it. He gently disinfected it several times a day. Until one afternoon, when he returned from the market, the inevitable had happened: they found her dead.

They went down to the yard, dug up the earth with a spoon and put her body in it, wrapped in a cloth. A simple ceremony.

[Manuel]: Ah, well, she is resting. She is no longer suffering and at least, well, we gave her the opportunity to experience something different, and now . . . 

[Juan Sebastián]: Manuel was sad, but he didn’t cry. Above all, he felt relief.

[Manuel]: I don’t know if there is something after death or not. If there isn’t, well, it’s simply over: that’s it, the suffering stopped. If there is, at least it’s no longer the physical part. That is, what we know as pain is not going to be present for sure.

[Juan Sebastián]: I asked Manuel why he didn’t sacrifice Manuela, not even when she was so sick, in her final days . . . but he wasn’t clear on that.

[Manuel]: That’s something that I will never know whether I did right or wrong. Sometimes it is also like taking on . . . the role of God: I am the one who decides when . . . when life ends and when . . . for how long I allow an animal to live. I don’t know. I don’t know what would have been better . . . and I think I’ll never know.

[Juan Sebastián]: In 2007, two years after Manuela died, Manuel returned to Colombia to work as a professor of Physiology at the National University, the same class in which, as a young man, he saw his professor mistreating a pigeon.

There he was in charge of a lab with his own rats for experimentation. He shared with students and colleagues all his knowledge in the area, but most of all, he tried to transmit something else to them: empathy in their relationship with experimental animals.

[Manuel]: How to respect other beings and be . . . find the best way to do research . . . If we are forced for now to use living beings for experimentation, then let’s do the best we can, right?

[Juan Sebastián]: This is what Manuel always repeats to his students: The Three R’s.

[Manuel]: Reduce the number of animals, refine techniques and replace where possible.

[Juan Sebastián]: Today, many scientists like Manuel promote these ideas around the world: use tissues, cells or computer models to reduce the use of animals, although these are still key in most medical advances. Experimenting on an isolated cell is not the same as on a living organism, in which hundreds of systems and organs interact, influencing each other in a network that is sensitive to any alteration.

Manuel believes that it is very difficult and that it will take us a long time to do without the use of animals altogether. But, as a good man of science, he trusts that one day we will have the knowledge and the technique to achieve it.

We talked with Manuel for hours, several times. Once in Bogotá, when he visited his family, and the rest of the times remotely, as he was in the United States and I was in Colombia. And always, in each of these sessions, I was intrigued by what Manuela had meant in his life . . . but I don’t think even he had very clear answers about that. Sometimes, the way he talked about her made it seem she had meant a lot, but other times I felt the opposite: that she had been just another pet, perhaps less important than the puppy of his childhood. And so, between conversations, he went from one mood to another.

Dutch primatologist Frans de Waal said that when he didn’t know what he was feeling or what his mood was, he went to the chimpanzees. He watched them, saw how they behaved towards him, and then he understood how he was. As if the gaze of those beings perceived things that even he did not understand about himself. I think that perhaps something like that happened to Manuel. He began to look at himself in the eyes of that rat who was no longer one of hundreds, who no longer had a number but a name, his own name. I imagine how he cared for Manuela those two years, how she generated affection, and their life together was full of contradictions: from the lab to the house, from experimentation to care and affection.

One day I asked him if his whole story with Manuela had not been, for him, a way to redeem himself from guilt, for all the rats he had sacrificed.

[Manuel]: Hmm . . . I don’t think I’ve ever asked myself that question. And it could be? Well, I have caused a lot of suffering and pain to experimental animals, and maybe deep down I would like to feel that . . . that I am somehow compensating for that. Maybe it was that, maybe . . . You often do things to try to ease your conscience. Reacting like that and taking Manuela out and giving her the opportunity . . . maybe it could be like a subconscious attitude of redeeming myself before my own world, right?

[Juan Sebastián]: Saving one animal to somehow save them all.

[Daniel]: Manuel is finishing his Ph.D. at Washington State University, where he returned in 2018. His project has nothing to do with sleep studies, but with the creation of a vaccine against a parasite that attacks cows, deer, dogs, cats, and also humans.

The vaccine is under development and Manuel has not had to work with animals anymore, although in the future it will be tested on cows, one of the species affected by this parasite. Thanks to this research, he is learning new molecular biology techniques, with which he wants to develop experimental models that avoid the use of animals as much as possible.

Today, 1040 labs, hospitals and institutions in the world are part of the programs of the International Association for the Evaluation and Accreditation of Laboratory Animal Care, an international organization that ensures responsible treatment of research animals.

[Maureen Stabile]: Hi, I’m Maureen Stabile, and I’m part of the DEAMBULANTES membership program. I support Radio Ambulante because it puts me in touch with the rest of the world and introduces me to stories that amaze me, educate me, touch me and entertain me. 

As part of the benefits, I was invited to read the credits for this episode. If you want more information on how to do that, go to


This story was produced by Juan Sebastián Salazar Piedrahíta and Nicolás Alonso. Juan Sebastián is a journalist and lives in Bogotá. Nicolás is an editor for Radio Ambulante and lives in Santiago de Chile. This story was edited by Camila Segura and Daniel Alarcón. Désirée Yépez did the fact-checking. The sound design and music are by Andrés Azpiri.

The rest of the Radio Ambulante team includes Paola Alean, Lisette Arévalo, Aneris Casassus, Emilia Erbetta, Fernanda Guzmán, Camilo Jiménez Santofimio, Rémy Lozano, Ana Pais, Laura Rojas Aponte, Barbara Sawhill, Elsa Liliana Ulloa, David Trujillo and Luis Fernando Vargas.

Carolina Guerrero is the CEO.

Radio Ambulante is a podcast by Radio Ambulante Estudios, produced and mixed on the Hindenburg PRO program.

Radio Ambulante tells the stories of Latin America. I’m Maureen Stabile. Thanks for listening.



Juan Sebastián Salazar Piedrahita and Nicolás Alonso

Camila Segura and Daniel Alarcón

Desirée Yépez

Andrés Azpiri

Sol Undurraga

Colombia and United States

Episode 25