Vivarium

For his mice the “sun” happened to rise between two and three in the morning, and so he, too, built his day around the artificial lights—even though increasingly this routine estranged him from the waking world. He’d pull in to a nearly empty parking lot, it would be him and the janitorial staff. He’d make his way down, down into the guts of the building, past airy lecture halls and glass-walled faculty offices, past some of the more expensive equipment on campus, including two eight million dollar fMRI machines—as if taking a tour of the daytime pomp his night-work made possible. The anteroom, in fact, to his little space contained something of a marvel, a thing they apparently invented here at the university. It was a huge sphere with a little styrofoam ball inside of it. A mouse, the experimental subject, would get perched atop the ball, which rotated freely on a bed of air. As the mouse ran, sensors picked up the ball’s motion; that, in turn, controlled a picture projected inside the sphere. Virtual reality. Meanwhile— this was what most impressed and galled him—the mouse was genetically engineered so that individual neurons could be sensed and stimulated by a laser. The result was that the mouse’s mind and its world were both under the scientist’s control. All this, however, required the mouse to have a rather large piece of skull removed and replaced with a Pyrex window. Scientists traveled from all over the world to use the sphere. Few of them, he guessed, thought about who cut the mouse’s skull open; or that in the corner of the room there was a small door marked VIVARIUM, where the bloody procedure took place. The vivarium was his office and had become his life. Inside it was dank and windowless and smelled like a pet store.

One winter evening, he stepped gingerly over the threshold of that door trying, as ever, to stay balanced while donning his shoe coverlets. In the past few years he had become top-heavy, and had difficulty bending over. Then came gown and bouffant cap. The gear was less for his protection than theirs. Most of the mice were bred into illness. He handled them constantly—for blood draws, injections, behavioral exams, feedings, breedings, and, occasionally, procedures ordered by the faculty. Recently he’d performed a gastric fistula as part of an experiment designed to see how gut trauma affected brain development. Puncturing the colon wall carries a high risk of infection, and he did not want to see a mouse wasted by his own carelessness.

An hour before, he was scraping ice from his windshield in the dark; inside the vivarium it was warm and day-bright. His cheeks flushed as he slumped into a stool. There were two rooms, each the size of a modest kitchen. A warren of small cabinets lined the walls below waist level, and above them, cages were stacked to the ceiling wherever you looked. The place was vibrating with small lives.

When the clamoring finally reached him, he rose, setting himself to various housekeeping tasks. He filled the water tanks, emptied the litter boxes, made sure the warming plates were on but not too hot. Of late this work had become a welcome distraction from the Becker experiment, and it reminded him that these animals were animals still. As he cleaned and mended, little scenes of life broke through. He’d catch a pup nursing, its tiny, pink form so fragile that you could see its heartbeat through its skin. Younglings with eyes too big for their heads yawned and stretched after waking up; he’d see them come to, disoriented and afraid, looking for their mothers. He never named his charges but a few of them lived here into old age, a little over two years, and he got to know them well. There were shy mice, lazy mice, mice that bristled at human contact and others that liked to perch in the crook of his arm.

He cleaned most of the lab’s glassware before finally allowing his attention to turn to a row just past the freezer in the back room. Instinctively, he reached for a mask in the pocket of his gown. As he knelt down below a placard reading “Becker: chromatin remodeling, PI: Leung,” he was greeted by an eerie tableau. There was a long row of small cages, all but one of them empty, with their doors ajar. These were marked on their cage-cards with a pink paper dot, denoting a euthanized animal. Some dots were worn to the point of peeling; some had clearly just been stuck on. The row smelled of bleach.

The Becker experiment had been running for nearly three years. At the beginning there were three dozen mice. Many had died shortly after weaning, from a flu-like infection that ran through the row. As it turned out they had been lucky. The survivors suffered indignities that in other experiments would have meant a swift and peaceful end. He looked over at the farthest cage. A mouse there had had a series of small strokes that left it paralyzed from the waist down; to keep the rest of its body from atrophying he had been encouraged to have it army-crawl on its exercise wheel. In the next cage over, a mouse with Crohn’s disease had refused to eat until it wasted to frailty. The Becker cages were smaller than normal because the mice so often required isolation.

Lab animals were not supposed to suffer unnecessarily—but necessary was a negotiation. He’d thought many times about filing a complaint but got no further than testy conversations with the postdoc. The guidelines were clear that “death cannot be used as an endpoint”—but this was exactly what Becker was doing. She was adamant that her mice be kept alive. When they got sick enough to euthanize, she’d insist he hold off just another week or two; he’d cave; the situation would degrade. When it got too ugly even for her he’d get the sullen order to put the mouse down.

There were only two left. Bec4 was in pitiful shape—awake, but lethargic, lazing in its own droppings. He grabbed it by the scruff, and gently rolled it over, wiping the filth underneath. Behind it, a litter-mate was sleeping. She was a very small thing. While he disinfected the floor of the cage he covered her with his hand so as not to wake her. Her whole warmth fit under his palm. He’d seen her and her brother grow up, play, fight, and comfort each other in sleep. She was wary, and liked hides and clutter. In all his time tending her she’d never crawled into his open hand; he’d have to palm her, or offer her a toilet paper roll to climb into.

As recently as two months ago both mice were in good health. He’d had to treat Bec4, the male, for mild arthritis. Now it had two kinds of cancer. The postdoc had insisted on chemotherapy, as if recovery were possible. Instead the injections had made it severely ill.

Mercifully, Bec4 was scheduled to be euthanized the following morning. It was strange, to know the moment another creature will die, when that creature itself does not know. He laid out some feed for the pair. Bec4 turned his head, seemed to think a moment, then slowly let it fall again. The little one warily approached, then darted back to her sleeping-place.

He wished he could finally end the experiment. He was eager to begin the process of forgetting it. Every demonstration of vigor in the sister—even now she was nuzzling up against the front of the cage, curiously following his movements—troubled him further. Soon she would end up like her brother, like all her litter. It did not matter how healthy she seemed. She was old.

The little mouse did not seem aware of that fact. She raced around the cage, around her brother’s sick-nest. She started hopping, hopping toward the door-latch, trying, it looked like, to get her keeper’s attention. For a moment it interrupted his gloom. The phrase “Anna K” bubbled to mind. If he had to give this little mouse a name that would be it, Anna, Tolstoy’s hero: vibrant, defiant, doomed.

After her brother was euthanized the little sister would be left with her own empty cage, one more in the row. The experiment would be down to its last subject. He saw himself coming back to this row each day, waiting for the turn. There would be a growth, or a refusal to eat, fever, lethargy. Whatever it was would progress. The postdoc would insist he do something, and he would, and this would only prolong the indignity. Seeing this as clearly as if it was happening a plan flashed to his mind and he did something he had never thought to do before.

Working under the hood, he dipped a cotton ball into a bath of isoflurane and propylene glycol, then covered it with a mesh platform. While the ball soaked, he quietly opened the cage and cupped Anna in his hand. He put her onto the platform and enclosed her quickly with a bell jar. In a minute or two the vapors would cause her to lose the righting reflex; a minute more, and her breathing would slow. At that point he’d remove her back to the cage with her brother. She would be sedated for seven or eight hours at least. Curled up the two mice would look similar enough. If his plan worked they would both have their peace tomorrow.

Meetings with the scientific staff were had in the daytime, the real daytime, and so after his shift he had only a few hours at home to sleep. He lived in a small split-level house in the suburbs a forty minute drive from the university. It was a two-bedroom, but after he’d rid himself of the last of his tenants, the second bedroom had gone over to boxes and other flotsam. The place sorely needed renovation. If you could somehow scrape off the wall-to-wall carpeting the floors would cower from the light. But no improvements were forthcoming. He could not afford them, and he did not want them. Owning his home he was free of a landlord—of every human encumbrance except a mortgage payment, which now he bore alone. He kept returning to the vivarium because the job kept him square with the bank; and because it kept his second bedroom free for boxes.

He made the drive back barely awake, squinting groggily through falling snow. The institute was buzzing when he returned. He liked to minimize his exposure to this, the actual life of the university. In line at the cafeteria were a few reasons why: in front of him, a gaggle of undergraduates, full of appalling energy; behind him, a distinguished professor, tenured into senescence, enjoying a slow decline. He stood awkwardly between them, of no status whatever, the wrong age and shape for the place. Taking a quick breakfast, he retreated with urgency to the false night of the vivarium. Inside, the animals slept and seemed to breathe together; the walls inhaled and exhaled. He inhaled and exhaled with them, again and again, until he, too, began to drift off.

He woke to the postdoc rapping on the door. She looked out of place and almost comic in her ill-fitting gown and cap—unbecoming, he thought, given their dread purpose. They were signing off on an execution, hopefully two. He sighed, then led her to the row while reciting Bec4’s medical history. Labored breathing began three months ago. An X-ray revealed a mass, determined to be metastatic lung cancer. Standard of care, twice-monthly chemotherapy. In follow-up scans, pancreatic cancer discovered incidentally. Meanwhile, treatment failed to clear the first tumor. The animal’s condition had degraded. It’s time. It was time a month ago. Look at him.

The postdoc studied the mouse she believed to be the dying Bec4, but was just Anna sedated. Standing over it, she seemed confused, almost angry. He could feel his cheeks getting hot. Bec4 was twice the size of Anna. They looked nothing alike. He thought of the disciplinary committee, his mortgage. He turned toward the postdoc, and took a breath, preparing an explanation.

I suppose we’re down to one, she said, looking through Anna’s small body. He let out a breath, staring at the postdoc. She had realized nothing, knew nothing. He couldn’t believe… It amazed him, how little scientists knew of their own animals. They were abstractions, known only as treatment or control. She couldn’t even tell male from female.

That’s what I wanted to talk to you about, he said, regaining his confidence. He drew the postdoc’s attention to the mouse who was actually sick: Bec4, whom the postdoc now believed was little Anna.
—This one’s not doing well either, he said.
—What? It was bouncing off the walls a week ago, the postdoc said.
—She decompensated.
—Decompensated?
—She rapidly got worse, he explained. Her lungs.

An alert, angry look came into the postdoc’s eyes. The experiment was on the line. Show me, she said.

His heart beat faster. His little grift was working. He poked the mouse, and showed it could not be roused. He offered it feed, and showed it would not eat. The postdoc was crestfallen, unbelieving. She said this mouse was in perfect health a week ago. There was nothing wrong with it.

He offered to take an X-ray of “Anna’s” lungs right then. It was a clever gambit. The postdoc took him up on it. Her experiment had been three years in the making and she could not accept its coming to nothing. The X-ray, of course, was incontrovertible. Bec4’s cancer had been brewing for months now. His lungs were a mess.

He returned both mice to their cage. They lay there side by side, unmoving. So what do we do, the postdoc said, backing away. The color had drained from her face. Walking in a daze toward the door, never to return, she answered her own question.

Euthanasia in the institute’s lab animals was governed by a set of guidelines put out by OLAC, the Office of Laboratory Animal Care. Because the life of a lab animal is already forfeit—its purpose is to serve the experiment, then die—the guidelines were aggressive. Conditions for euthanasia included “weight loss greater than 10% of baseline weight; clinical signs of illness such as hunched posture, respiratory difficulties, or reticence to move.” One section explained that if you came across dead or cannibalized pups, you should check the others for milk in their stomachs, to determine if they were nursing. If not, you should kill them before they starved.

Euthanasia was to begin with a lethal dose of analgesic—isoflurane, clonidine, chloral hydrate, fentanyl, methadone, pentobarbital, morphine; or for groups, a chamber filled with carbon dioxide (up to ten mice at a time)—but the guidelines were clear that there were to be no half measures. “Prior to carcass disposal, an additional physical means of ensuring euthanasia must be performed.” Options included “cervical dislocation, bilateral thoracotomy, decapitation, and exsanguination.” By cervical dislocation they meant a maneuver where the neck is prised from the spinal column with thumb and forefinger. His lab, like most in the university system, had settled on decapitation because it was simplest. For mice they used a commercial-grade guillotine, the blade as wide as a pocket notebook; you were to sharpen it every 250 uses.

Neither Bec4 nor Anna had moved since the postdoc left. Seeing that Bec4’s breathing was fitful and labored, he delayed no further. He prepared the same isoflurane and propylene glycol bath as the night before, then plucked Bec4 by the tail and enclosed him in the bell jar. This time he waited more than a minute.

The sick thing about the OLAC guidelines is that you are supposed to watch the whole time the animal is dying. The idea is that if they have an unusual or violent response to the analgesic—an allergic reaction, say—you can intervene to prevent further suffering. In all his years, of course, this had happened exactly zero times, and so he’d gotten into the habit of distracting himself while the life drained out of his patient.

Now, though, he found himself paying close attention. He watched regularity return to Bec4’s breathing and then, a few minutes later, a dullness come over the eyes. He watched the limbs slowly slacken, then stiffen. He only looked away at the drop of the guillotine.

When he returned to Anna’s cage these images were fresh in his mind. But something was wrong—something missing—the little mouse was not where he’d left her. She must have woken up. She couldn’t have escaped—no, yes, she was still here, in the wheel, not spinning it but rather crouching inside. He laid down a bit of feed by the door; she’d be starving by now, recovering from the sedative. She glanced his way a moment but then, defiant again, stayed put. He smiled, then picked her up by the scruff.

For the last time, he put her under the jar. As he did so he felt a sense of peace. He was doing the right thing. As the first minute lolled into the second, though, and her breathing slowed, he began to imagine what was coming next. He would see the legs stiffen; he would hear the shimmer of the blade as it fell; and just as he was imagining this sprightly old mouse with her head rolling beside her he had tipped open the jar and curled the intact body into his hand, his palm mouse-warmed, and put it—her—into the smallest box he could find. Before he understood why, he was out in the hallway, striding toward the elevator. A student was there, waiting to go up—busy this time of day—and she looked curiously at his hands, at his face, his hands again, skeptical. What’s that you’ve got there, she asked. The elevator dinged open and without answering he covered the box with his hip and turned toward the stairs instead, straight to the parking lot, ambling toward his car, bleary-eyed in the glare of the real sun.

He woke up after nearly thirteen hours to the faint memory of shame, as if he’d gotten drunk. He could hear shoe-paper being crumpled. Something by his bedside was juddering. He must’ve upgraded her into a shoebox. With some effort he rose from bed. He brought the shoebox into the bathroom and closed the shower door behind him and covered the drain. Taking a seat on the shower floor, he cracked open the box and peeked inside. The small mouse looked alert, and wary—curious, clearly, about the turn its life was taking. If he could have seen himself he might have looked the same way. It was the first time he’d had a house-guest for more than four and a half years.

He considered the box between his legs. To tide Anna over he’d put some banana and yogurt in there, which she’d picked clean. The reality of what he’d done came to him now in quick pulses. He had sabotaged an experiment; by all accounts it was an important one; certainly it was important to the postdoc, who if she found out…

He calmed himself by thinking of what he would do next. He would have to buy a proper supply of feed. He would have to get a real enclosure and find a place to put it. Getting to his feet now, box in hand, it occurred to him that Anna hadn’t ever left the dank little room she was born in. She would have died having never seen the sky. The idea made him proud at first, but then oddly self-conscious, seeing his house through the eyes of another living being who took it to be fully one half of the world. It was not in the best condition. Actually there was shit everywhere. Another thing he’d have to do, he said aloud now to the box, coming into the living room, is tidy up a bit. Maybe he could put her by a window.

As he prepared breakfast, including a makeshift meal for Anna, he narrated his routine to the box. He had breakfast long after most people had eaten dinner. He liked to have TV on in the background, but usually ended up watching YouTube on his laptop. His YouTube these days was full of airline pilots and survivalists, for some reason. Nothing about vets, pets, mice, or science. At this he caught himself, and realized that he had to leave for work. He apologized to the box before punching a few small airholes in it and wrapping the lid tight with a rubber band. He said he wouldn’t be long.

He couldn’t believe how careless he’d been and he felt an awful emptiness and cruelty toward himself as he paced the kitchen, looking now and again at the shoebox with an Anna–sized hole gnawed into the side of it. He saw in a flash his whole house, the yard, neighborhood, the vastness of the actual world to a mouse accustomed to cages. He saw himself rummaging through the closet, running around the neighborhood, and how ridiculous that would be. It was done.

His mind returned to his kitchen and he saw the place with fresh eyes. It was bare, small, and shoddy. For a man of his age and education it was an embarrassment. He was an embarrassment.

The feeling sat in his stomach. It was a telescoping, reeling sensation. He saw the last ten and the next ten years of his life. Lurching from the sight, nauseous, he scrambled to the bathroom believing there might be relief in a hot shower. But with the water pooling by his toes all he could think of was the emptiness of his house, his days and nights, his whole life—and how frightening it was that this awful fact, now brought to light, could not be quieted; that he was a ruin; the thought made him feel worse and emptier and a panic rose, his heart pounded, and he tried to focus on the water on the top of his head.

By the time he got out and toweled himself off, and got dressed for bed, he had calmed down some. He needed to eat something.

When he opened the pantry he jumped back and audibly yowled—a mouse in his food—before realizing it was Anna, and she had just been hiding. He sometimes told himself that he no longer even loved animals but the tears that came into his eyes were the whole truth.

It was the first time in so long that he’d had a companion. At work he had begun to treat his animals as accessories to the experiments. The trouble was that if you didn’t think this way you couldn’t work in a vivarium very long, or in science. The cruelty was just too immense. He thought often about a statue, in southwestern Siberia, at the Novosibirsk Institute of Cytology and Genetics. It was apparently the world’s only monument to lab animals—a statue of a huge mouse with the kind face of an old man, wearing glasses, contemplating a strand of DNA as if it were a bit of knitting. It was meant to be a tribute. But wasn’t it perverse, to condemn a thing and then celebrate its sacrifice?

In his own lab, the closest thing to a monument was the sphere outside the vivarium. When it was first unveiled, it was celebrated by the university and covered in the national press as a “particle accelerator for the brain.” He’d gotten swept up himself. Walking past it each night, he’d felt a swell of pride: if anything truly powered the great machine, it was his work preparing the mice. Nowadays the same thought haunted him.

Anna was thankfully no longer an experimental subject. She lived in his house, on a table by a big north-facing window. In the vivarium she had been shy. In her new enclosure, five times the size of her old cage and far busier with places to hide and bits of natural food to forage, she warmed up. She crawled readily into his palm. He did not know how long she had to live but he set about making her last days good, one good day after another. He played with her. One day he crafted a little obstacle course of hurdles, a tube, and a series of ladders. He trained her to collect coins and put them in his hand in exchange for a treat. He’d hold her and pet her cheeks while she slept.

Mice are social creatures. In isolation they become depressed, same as a person. Anna had lived her whole life with her litter before each one of them had been taken away as it began to get sick.

The days ran on. He set up little comfortable lying spots around the house, in old shoes and in the clutter of the box room. He’d toss her tiny morsels of whatever he was eating. They settled into a routine. He began to anchor his existence less to the rhythms of the workday and more to her cycles of feeding, playing, and sleeping. He couldn’t believe how much she ate—fully twice the usual allotment of pellets, and more than that if you considered her size and age. He began to buy bigger bags of feed to save money.

After a run to the store one day, he glanced at the expiration date of the bag he was replacing and saw that it was in September, which didn’t make any sense, too much time had passed, Anna should have gotten sick by now, she should not even be alive.

He knew then that Anna was unusual in some way. She was small, and yet always hungry, and had survived many months beyond the lifespan of a typical laboratory mouse. In all their time together she hadn’t slowed. Still, the significance of these facts did not truly hit him until much later, midway into their second year together at home, as she lay at his feet one weekend night, nosing at a cashew. A simple thought bubbled to him out of nowhere. The thought was, Anna was not a control in the postdoc’s experiment.

He rarely troubled himself with the details of the lab’s research. He had been trained as a veterinarian, not as a scientist, and had difficulty with the jargon of molecular biology. He had not read an academic article since he’d taken his first full-time job, and had not stepped foot in a library since well before that. But he went there now in search of a particular reference.

In the graduate biosciences library, besides the regular bevy of books and journals, there was a small section of stacks devoted to the work of the university’s own students. Ph.D. theses and monographs lined these back shelves in tall, black, perfect-bound volumes—most of them crisp and never opened.

He scanned the row of A-Es, not sure what to expect—expecting to find nothing—and almost startled when he saw the name “Becker, J.” running vertically down a spine. The gruesome details of that experiment, that era, rushed through him in a flash. He had half a mind to turn home, or to toss the book without reading it. But curiosity overcame him and he looked down the stacks, one way then the next, before tipping the book off the shelf, and stole quickly into a carousel at the edge of the floor.

The reading was slow-going. The particulars eluded him—even some of the broad strokes eluded him—but with long effort he began to understand the story told in “Chromatin remodeling via ‘master regulator’ methylation sites in the senescent epigenome.” This was clearly the work of many years. It described a theory of cellular inflammation and metabolism, “apoptosis” and DNA repair, a theory of aging, that in the author’s own telling would have extraordinary consequences if true. It also described a series of experiments to test this theory. This was the part of the book that he could understand. The experiments had unfolded under his watch; he knew them well. He was surprised to find that they were rendered here in spare, unflinching detail. Becker did not dissemble what she’d done. The last and longest-running of the experiments, she wrote, had been catastrophic: the subjects had all died. The rest of the paper proceeded from that fact. Becker eviscerated her own theory. In the conclusion she practically apologized. She deemed the whole line of thinking a scientific dead end.

Resting the book on the narrow desk in front of him, he thought back to his last interactions with the postdoc. Around the lab she had been considered something of a star prospect. Her advisor prized boldness—the whole lab did—and no doubt this is part of the reason she pushed her experiments so far. But there was another reason. She genuinely believed that the mice she had been treating would recover, or would not get sick in the first place, would not age, would not die. Anna, the last of her subjects, had outlived all the controls, and had seemed for a time to be giving proof to the theory. She was in excellent health; she was the postdoc’s last hope. Anna’s apparent turn toward cancer, following the sudden turns of all the other subjects, felled in one stroke a half-decade of work. The postdoc had staked her scientific life on these mice and when the last of them died her career died with it.

Satisfaction, and wonder, came over his face as he thought of Anna back home in her enclosure. About now she’d probably just be waking up. Anna—his Anna. She was not a failure as the postdoc believed her to be. She was something else entirely. She had not developed cancer, nor any of the standard maladies of age, including any cosmetic or cognitive deficits. He guessed that if she hadn’t been spayed she might still be fertile. She had all the same energy as the day he took her home. She was the grail and he was her keeper.

Time passed. He dwelled often on his secret, as if worrying a ring in his pocket, for it gave him a sense of purpose and immense power. All it would take is a single message to the postdoc—that little mouse is still alive—and the fact would change the world as nothing has.

But he knew exactly what would happen to Anna if anyone found out what she was—what would become of her long, long life. She would be the subject of many experiments. The thought was intolerable. So what was left to do?

They spent their days together, as before. But time did not stop for him the way it stopped for her. He could not keep her here, in this house, while he grew old. It was not a good place to live forever. No place was, really. So he made a decision that would become its own kind of secret. One morning he lowered Anna into a shoebox and drove a few hours into the country. He found a meadow he liked off a quiet hiking trail and let her out. She stuck by him for a moment, but as she turned, curious to explore, he slipped back into his car and drove away. He hoped she would see something of the world. And with any luck she’d die well. ∎