My wife and I bought an old house two years ago. The house was a rental, and there was evidence that mice were living in it. Mice can carry disease, and high on my list of things-to-do was to kill them. I bought some old fashion snap mouse traps, baited them with peanut butter, and after a few days, I killed a mouse.
The trap had broken the mouse’s spine as he sampled the peanut butter. The force of the snap caused so much blood to come out of the mouse’s mouth, that I discarded both the trap and the mouse together.
I am a brain tumor researcher. I am currently working on treatments for glioblastoma, a very aggressive type of brain tumor. Glioblastoma often affects young and middle aged people, and the prognosis is poor. Currently more than 90% of patients that have a glioblastoma don’t survive more than 5 years. Death within one year of diagnosis is common.
In my line of work, I give glioblastomas to mice. I implant tumor cells into their brains, and the tumor grows, not unlike it does in people. Sometimes I implant tumors in mice in order to develop better tumor-imaging techniques. However, most often, I am testing an anti-tumor treatment.
In a typical experiment, I will implant brain tumor cells in ten mice. Five mice will not receive treatment, and five mice will. For example, recently I found that a particular protein increases the survival, growth and migration of glioblastoma cells in vitro (in a culture dish). After some more experiments, I found that a particular inhibitor of this protein could reduce the survival, growth and migration of glioblastoma cells. As a result, I decided to test whether or not application of this protein inhibitor could improve the survival of mice that were implanted with brain tumors.
I implanted ten mice with glioblastoma. I treated five of these mice with the inhibitor, and did not treat the other five. After two weeks, I killed the mice, and then inspected their brains. I found that the five mice that had been treated with the protein inhibitor had much smaller tumors than those that had not been treated. This was a positive result; however, it was only the beginning. I now had many more questions that I needed to answer. Some of these questions were:
-Would the treated mice be cured if I continued to apply the protein inhibitor? -Would increasing the dose of the inhibitor shrink the tumors even more? -Would increasing the dose of the inhibitor have negative effects upon the mice? For example, perhaps a higher dose would better kill the tumor, but induce a stroke in the mouse. -Did the inhibitor affect the survival, growth and migration of the tumor in the mouse, or only one or two of these properties of the tumor? -Could combining this inhibitor with another drug better treat the tumor? -Which drug would be likely to be beneficial to use in tandem with this inhibitor to fight the tumor?
There are many more questions to be answered, but these are some of the most obvious.
Now, let me talk about killing mice in my work. When I give tumors to mice, they suffer. It is not obvious immediately, but after several days, the mice that have brain tumors become somewhat lethargic, and they often eat less. In fact, we have a staff of animal care technicians, headed by a veterinarian, who closely monitor the health of our mice. If a mouse is suffering too much, or if it has experienced too much weight loss, we kill it, regardless of the time-course planned in our study.
When we kill our mice, we start by giving them a strong general anesthetic. The mouse is rendered unconscious, and then we will either decapitate it, or drain it of its blood. It is often useful to drain the mouse’s blood, because when you are later probing the tissue for specific proteins, abundant blood cells can obscure the results.
When I want to implant tumors in mice, I need to submit an application to an animal care committee. The committee is composed of several people, some are from our institute, and some are from outside. There are scientists, veterinarians, and at least one non-scientist on the committee. The committee accepts applications once each month, and it usually takes one month before an application is reviewed. This application is roughly 20 pages long, and includes every detail about a study, its objectives, and how the mice will be treated. It usually takes me two weeks to write a new application. Typically, the animal care committee will want additional information, or clarification, and I will be asked to resubmit the application to them after addressing these issues. On average, it takes about three months from starting an application to its approval. I have not had an approval rejected.
If at any time, I want to alter my experimental plan, I need to submit an amendment to my application. These amendments are a few pages long, and approval of these amendments typically takes one month. If I want to try another treatment, I need to submit a new application.
In the course of my work, I design and run experiments, I write papers that report my findings, and I submit grant applications to get money so that I can pursue new ideas and treatments. Due to the extensive time and effort that is required for a new application, I need to carefully consider applying for animal experiments. Several times I have chosen not to test a new tumor treatment because the application process requires such time and effort.
We will eventually find a successful treatment for glioblastoma. However, based on my experiences and those of my colleagues, I know that this cure will come later than it would, were there less bureaucracy involved in experiments involving mice. I believe that less people would die of glioblastoma if the application process for experiments involving mice were significantly simplified.
Anyone can purchase a mouse trap and kill a mouse without approval. Some of mouse traps, like glue traps, involve capturing and starving the mouse to death. Mouse bait causes a mouse’s blood vessels to hemorrhage, and the mouse dies of internal bleeding. If you are quick, you might stomp on a mouse with your boot.
I kill mice both at home and at work in an effort to prevent disease. However, when I am at home, I don’t need to submit paperwork.