Euthanizing mice
The other day I was over at Rachael's house, and the topic of research-on-animals came up. Rachael is many things, of which the relevant ones are: highly empathetic (maybe even Empathetic, I can't tell); hyperenthusiastic about animals and the environment; very protective of, and caring for, the same.
To her credit, she did not go on a long animal-rights diatribe about how I am a murderer for participating in research on animals. (BTW, this does not reflect lack of such sentiments on her part. I'm not sure how she feels about animals dying for medical research.) She just asked me how I dealt with it. I couldn't really give a good answer at the time. Something like "I just push it aside; yes, it's disturbing, but we try to be as humane as possible, and I push it aside."
It is difficult to deal with the suffering and death of research animals.
I have been interning in a neurobiology lab. Luckily, the only organisms we work with are mice and bacteria. (I feel so sorry for the people who work with monkeys.) This post will be about mice. Bacteria are not worth discussing.
Actually, the first time I worked with mice was two summers ago, when I interned in a different neuroscience lab. I only went in once a week, and I hardly knew anything about what we were studying so I couldn't really make a substantive contribution...blah blah blah. Anyway, that was the first time I had to deal with mice in a research setting.
I remember how freaked out I got the first time I watched Helen handling the mice. To pick them up, you pull them up by the tails and then scruff them. To obtain a very small tissue sample for genotyping, you cut off the tip of their tail. To number them, you use a predefined code that involves cutting off toes (and sometimes punching holes in ears, though I didn't see this). The mice would get frightened, squeak, writhe, urinate, try to escape, try to bite, and eventually, bleed. I was quite surprised at the amount of blood left on the table when we finished numbering and tailcutting a couple cages of mice.
Thankfully, that was as much as I had to do while interning with Helen. I did do some sectioning and staining of mouse brains, but they had already been dissected out, and I was able to think of them as just tissue. Meat. They were just excised brains, they didn't look at me with cute little button eyes and squeal, demanding to be put back in their cage with all their paws intact.
At one point, Helen and I walked past a guy who was doing a more elaborate procedure. The mouse was on its back on a styrofoam block, pinned by the paws -- essentially crucified flat. Its chest was cut wide open, and I could see its heart beating. There was blood everywhere, and lots of tubes going back and forth from the mouse to this little bit of whirring apparatus in a corner. It would have thoroughly blown my mind, but I didn't catch more than a brief glimpse. Anyway, except for that, my mouse involvement was relatively pain-free in that lab.
I got a bit of a shocker when I started interning with John last summer. We were doing a project that involved acutely isolating astrocytes. Translation: killing young mice, dissecting out their cerebral cortices, and processing those in various complicated ways to finally end up with an isolate of single cells of a certain type. That procedure takes pretty much all day, and is called a "prep".
Oh, I thought tailcutting and toecutting were bad? To kill a young (recently or not yet weaned) mouse, you behead it with scissors. The body twitches, and the head falls onto the table, and it twitches too. Blood wells and drips out of the body, reddening about a square inch of the paper towel bed you do dissections on (that's for a pretty small mouse -- I never worked with adult mice). You discard the body in a biohazard bag. Meanwhile, the head is sitting on the table, looking for all the world like a live mouse, except with the body missing. The jaw opens and shuts, and the head rocks back and forth. It takes about ten seconds to go quiescent, and then you unroof the skull and dissect out the cortex.
Sometimes, when you put the scissors up to their neck, they squeal and put their little hands up, and grasp the blade, and you can't behead them without cutting off their fingers.
The first time I watched John do it, and the first time I did it myself..........I'd like to say I felt faint, or nearly threw up, or something overt like that. But I just felt a deep sort of quiet horror that didn't lend itself to being expressed that way. I didn't feel a physiological effect, like faintness or nausea; just a quiet horror and mental revulsion. But I wondered, what was wrong with me? Why wasn't I more upset? As unpleasant as the experience was, I wanted it to feel more unpleasant. I didn't want to feel the beginnings of numbness and desensitization.
I did many preps that summer, averaging two a week, I think. And I enjoyed most of the tissue-culture work, the part where you're working with bits of tissue or cells in a tube, instead of with whole (or less-than-whole) animals. The summer's work as a whole was fun and challenging and rewarding and all sorts of awesome adjectives like that. But I was doing two preps a week, and often there were tight time constraints, so I didn't spend much time hyperventilating over dead mouse pups. I didn't actually become numb, but I grew much better able to put the horror aside quickly and move on to the next thing that needed to be done. And in five minutes, the disturbing part was over, and there was just tissue bits in a dish. Meat.
One thing that broke the "wall" for me was perverse, macabre humor. It made me realize anew what awful things we had to do, while helping me cope and smile. For example, the other people in the lab had put up a little poster over the gas-chamber used to euthanize adult mice: "Dr. Kevorkian wants YOU to keep the euthanasia area clean!", written below a photo of Kevorkian doing that pointing-at-the-viewer thing from the Uncle Sam Wants YOU posters. There was a tradition of referring to the older pups as "pupcorn", because they would jump about when you opened the cage, and they could jump high enough to escape if you weren't careful. My favorite was this random thing that happened to me. Immediately after beheading the pup, you cut away the skin on top of its head using small scissors. John's small scissors squeaked. The first time I used them, I jumped about a mile all "OMG OMG OMG it's still alive it squeaked WTF OMG AAAAAAAACCCCKK", until I realized that the mouse head had no vocal tract, so it couldn't possibly be squeaking. After that incident, I could laugh whenever the scissors squeaked.
This summer, I'm back in the same lab, working with a different grad student (Lynette). I did another prep last week (IIRC), and I didn't have much trouble re-acclimating to the lab, the preps, and the mice dissection.
A couple days ago, I watched another student do a "perfusion", which involves pumping out all a mouse's blood and replacing it with saline solution, then pumping that out and replacing it with preservative. This turned out to be the same procedure that I saw back when I was with Helen, with the mouse crucified, heart beating, all that. I watched it. I got a little nauseous, but not really that much. I knew the mouse was unconscious and completely unaware of what was happening to it; everyone takes great care to make sure that the animals are well and completely anaesthetized. Sure, it bothered me, but not overly much; and pretty soon it was back to the "it's just tissue" stage.
This morning, I watched Lynette euthanize four cages of mice. (I participated obliquely, by carrying cages and suchlike; I passed up the offer to participate directly.) We put a cage into a gas chamber and turned on the CO2. The mice gradually slowed down and got quiescent, and eventually they went from asleep to dead. You could tell they were dead when their eyes turned green.
After gassing the mice, you had to verify that they were dead. This meant holding the tail with one hand, and pinching the neck with the other, and breaking their necks. I passed up on the offer to try my hand at this, though I had the feeling I probably should have gone for it.
It wasn't arbitrary. These mice were killed because they were not useful. They did not carry enough copies of the mutation we needed. Some of the mothers had been in the habit of having litters and then eating them. (That, BTW, is a natural mechanism: when the environment is lousy for raising pups, the mother will eat them to conserve protein, protein being not exactly abundant in a mouse's natural diet.) Litters would be the wrong age at inconvenient times. One of the females was pregnant, but the pups would be too old by the time anyone could do anything useful with them, just because of everyone's schedules. No one keeps extra mice around for their own sake; it's a hassle to take care of them, and it wastes funding better spent on expensive experimental apparatus and reagents. I accept all of that.
(I would have offered to adopt them, but I'd asked about that at Helen's lab. For one thing, mice with poorly-understood mutations make dangerous pets. For another, it's a bad idea for mouse researchers to keep pet mice of any kind, in case the pet mice get a disease and the researcher carries it into the mouse colonies at the lab.)
It was relatively OK to kill mice for a prep, because they were dying for a reason, and their cells were being put to good use. Even part of them lived on; though we killed the mice, we spent every effort nurturing its glial cells to grow and thrive. They were contributing to science, and might one day contribute to human medicine. But the euthanasia was useless and pointless, and that was what got me. These mice were not being used for anything. They were just extra, and there was no room for keeping extra mice.
EDIT: forgot to write this bit before. While I watched the euthanasia, I tried not to block it out or push it aside. I wanted to feel horror and revulsion. I wanted to be upset. I made a point of looking at their faces when Lynette said she always tried to avoid it. Things like that. I wanted to make sure I hadn't gone numb.
It's not like there's a machoness culture around this in the lab, fortunately. You don't get ridiculed for being upset about the animals suffering and dying; at most, you get a few odd looks, and a suddenly solicitous mentor. We spent half an hour discussing how badly we felt for the people in another lab who had to kill a monkey. They had known this monkey, had worked with it for months, had trained it to do things, had even named it. And now they had to kill it and extract its brain. We were very glad we were not them.
To her credit, she did not go on a long animal-rights diatribe about how I am a murderer for participating in research on animals. (BTW, this does not reflect lack of such sentiments on her part. I'm not sure how she feels about animals dying for medical research.) She just asked me how I dealt with it. I couldn't really give a good answer at the time. Something like "I just push it aside; yes, it's disturbing, but we try to be as humane as possible, and I push it aside."
It is difficult to deal with the suffering and death of research animals.
I have been interning in a neurobiology lab. Luckily, the only organisms we work with are mice and bacteria. (I feel so sorry for the people who work with monkeys.) This post will be about mice. Bacteria are not worth discussing.
Actually, the first time I worked with mice was two summers ago, when I interned in a different neuroscience lab. I only went in once a week, and I hardly knew anything about what we were studying so I couldn't really make a substantive contribution...blah blah blah. Anyway, that was the first time I had to deal with mice in a research setting.
I remember how freaked out I got the first time I watched Helen handling the mice. To pick them up, you pull them up by the tails and then scruff them. To obtain a very small tissue sample for genotyping, you cut off the tip of their tail. To number them, you use a predefined code that involves cutting off toes (and sometimes punching holes in ears, though I didn't see this). The mice would get frightened, squeak, writhe, urinate, try to escape, try to bite, and eventually, bleed. I was quite surprised at the amount of blood left on the table when we finished numbering and tailcutting a couple cages of mice.
Thankfully, that was as much as I had to do while interning with Helen. I did do some sectioning and staining of mouse brains, but they had already been dissected out, and I was able to think of them as just tissue. Meat. They were just excised brains, they didn't look at me with cute little button eyes and squeal, demanding to be put back in their cage with all their paws intact.
At one point, Helen and I walked past a guy who was doing a more elaborate procedure. The mouse was on its back on a styrofoam block, pinned by the paws -- essentially crucified flat. Its chest was cut wide open, and I could see its heart beating. There was blood everywhere, and lots of tubes going back and forth from the mouse to this little bit of whirring apparatus in a corner. It would have thoroughly blown my mind, but I didn't catch more than a brief glimpse. Anyway, except for that, my mouse involvement was relatively pain-free in that lab.
I got a bit of a shocker when I started interning with John last summer. We were doing a project that involved acutely isolating astrocytes. Translation: killing young mice, dissecting out their cerebral cortices, and processing those in various complicated ways to finally end up with an isolate of single cells of a certain type. That procedure takes pretty much all day, and is called a "prep".
Oh, I thought tailcutting and toecutting were bad? To kill a young (recently or not yet weaned) mouse, you behead it with scissors. The body twitches, and the head falls onto the table, and it twitches too. Blood wells and drips out of the body, reddening about a square inch of the paper towel bed you do dissections on (that's for a pretty small mouse -- I never worked with adult mice). You discard the body in a biohazard bag. Meanwhile, the head is sitting on the table, looking for all the world like a live mouse, except with the body missing. The jaw opens and shuts, and the head rocks back and forth. It takes about ten seconds to go quiescent, and then you unroof the skull and dissect out the cortex.
Sometimes, when you put the scissors up to their neck, they squeal and put their little hands up, and grasp the blade, and you can't behead them without cutting off their fingers.
The first time I watched John do it, and the first time I did it myself..........I'd like to say I felt faint, or nearly threw up, or something overt like that. But I just felt a deep sort of quiet horror that didn't lend itself to being expressed that way. I didn't feel a physiological effect, like faintness or nausea; just a quiet horror and mental revulsion. But I wondered, what was wrong with me? Why wasn't I more upset? As unpleasant as the experience was, I wanted it to feel more unpleasant. I didn't want to feel the beginnings of numbness and desensitization.
I did many preps that summer, averaging two a week, I think. And I enjoyed most of the tissue-culture work, the part where you're working with bits of tissue or cells in a tube, instead of with whole (or less-than-whole) animals. The summer's work as a whole was fun and challenging and rewarding and all sorts of awesome adjectives like that. But I was doing two preps a week, and often there were tight time constraints, so I didn't spend much time hyperventilating over dead mouse pups. I didn't actually become numb, but I grew much better able to put the horror aside quickly and move on to the next thing that needed to be done. And in five minutes, the disturbing part was over, and there was just tissue bits in a dish. Meat.
One thing that broke the "wall" for me was perverse, macabre humor. It made me realize anew what awful things we had to do, while helping me cope and smile. For example, the other people in the lab had put up a little poster over the gas-chamber used to euthanize adult mice: "Dr. Kevorkian wants YOU to keep the euthanasia area clean!", written below a photo of Kevorkian doing that pointing-at-the-viewer thing from the Uncle Sam Wants YOU posters. There was a tradition of referring to the older pups as "pupcorn", because they would jump about when you opened the cage, and they could jump high enough to escape if you weren't careful. My favorite was this random thing that happened to me. Immediately after beheading the pup, you cut away the skin on top of its head using small scissors. John's small scissors squeaked. The first time I used them, I jumped about a mile all "OMG OMG OMG it's still alive it squeaked WTF OMG AAAAAAAACCCCKK", until I realized that the mouse head had no vocal tract, so it couldn't possibly be squeaking. After that incident, I could laugh whenever the scissors squeaked.
This summer, I'm back in the same lab, working with a different grad student (Lynette). I did another prep last week (IIRC), and I didn't have much trouble re-acclimating to the lab, the preps, and the mice dissection.
A couple days ago, I watched another student do a "perfusion", which involves pumping out all a mouse's blood and replacing it with saline solution, then pumping that out and replacing it with preservative. This turned out to be the same procedure that I saw back when I was with Helen, with the mouse crucified, heart beating, all that. I watched it. I got a little nauseous, but not really that much. I knew the mouse was unconscious and completely unaware of what was happening to it; everyone takes great care to make sure that the animals are well and completely anaesthetized. Sure, it bothered me, but not overly much; and pretty soon it was back to the "it's just tissue" stage.
This morning, I watched Lynette euthanize four cages of mice. (I participated obliquely, by carrying cages and suchlike; I passed up the offer to participate directly.) We put a cage into a gas chamber and turned on the CO2. The mice gradually slowed down and got quiescent, and eventually they went from asleep to dead. You could tell they were dead when their eyes turned green.
After gassing the mice, you had to verify that they were dead. This meant holding the tail with one hand, and pinching the neck with the other, and breaking their necks. I passed up on the offer to try my hand at this, though I had the feeling I probably should have gone for it.
It wasn't arbitrary. These mice were killed because they were not useful. They did not carry enough copies of the mutation we needed. Some of the mothers had been in the habit of having litters and then eating them. (That, BTW, is a natural mechanism: when the environment is lousy for raising pups, the mother will eat them to conserve protein, protein being not exactly abundant in a mouse's natural diet.) Litters would be the wrong age at inconvenient times. One of the females was pregnant, but the pups would be too old by the time anyone could do anything useful with them, just because of everyone's schedules. No one keeps extra mice around for their own sake; it's a hassle to take care of them, and it wastes funding better spent on expensive experimental apparatus and reagents. I accept all of that.
(I would have offered to adopt them, but I'd asked about that at Helen's lab. For one thing, mice with poorly-understood mutations make dangerous pets. For another, it's a bad idea for mouse researchers to keep pet mice of any kind, in case the pet mice get a disease and the researcher carries it into the mouse colonies at the lab.)
It was relatively OK to kill mice for a prep, because they were dying for a reason, and their cells were being put to good use. Even part of them lived on; though we killed the mice, we spent every effort nurturing its glial cells to grow and thrive. They were contributing to science, and might one day contribute to human medicine. But the euthanasia was useless and pointless, and that was what got me. These mice were not being used for anything. They were just extra, and there was no room for keeping extra mice.
EDIT: forgot to write this bit before. While I watched the euthanasia, I tried not to block it out or push it aside. I wanted to feel horror and revulsion. I wanted to be upset. I made a point of looking at their faces when Lynette said she always tried to avoid it. Things like that. I wanted to make sure I hadn't gone numb.
It's not like there's a machoness culture around this in the lab, fortunately. You don't get ridiculed for being upset about the animals suffering and dying; at most, you get a few odd looks, and a suddenly solicitous mentor. We spent half an hour discussing how badly we felt for the people in another lab who had to kill a monkey. They had known this monkey, had worked with it for months, had trained it to do things, had even named it. And now they had to kill it and extract its brain. We were very glad we were not them.