Dear College of Science Faculty and Staff,
This week you might have read how human neurons, the cells that receive and send signals around the nervous system had been implanted into a rat brain. The human neurons thrived and integrated into the rat brain so that when they were stimulated, the rat’s behavior changed. This is another step in the surprising understanding that cells can ‘self-organize’ to form small bits of human organs, called ‘organoids’. These can assist in understanding disease and devising treatments that can help. In this study, to assess function, the brain organoid was implanted into a rat brain. Is it ethical to use rats as hosts for human neurons, possibly bits of the human brain? How much of the rat brain can, and should maximally, be replaced by human cells? The answers to these complex questions include data and opinion, ethics, in other words.
Let’s be clear. Without experimentation on animals, almost none of us would be here to read this. Every medicine, every type of vaccine has been through animal testing. Every disease treatment has used animals to understand a possible strategy for people. A major part of the fundamental work that has led to these treatments, and that is nowhere near complete, has relied on experimentation in non-human animals. Work that seeks to understand the chemical signals that govern cellular life and death, to understand the minute control of the immune system, to uncover the detailed workings of organs, on and on.
And because the data obtained from this work are so precious, the ethical use of animals in experimentation is a critical consideration. For many years I taught an Ethics of Animal Experimentation module to PhD students and Postdoctoral trainees, as required by the NIH and NSF. It was a soul-searching assignment for both students and teacher. We began by considering the policies and laws around care and use of animals. At Northeastern University, our excellent Division of Laboratory Animal Medicine ensures that every animal we use is carefully looked after, every day, in compliance with Federal Laws.
With the students, I posed a set of questions that included: Do humans have the right to experiment on animals? Do animals have equivalent rights to humans? Do you think it is more permissible to experiment on certain species of animals? Over the years the conversation changed. When I started teaching the module, some students would challenge that we did not know whether animals felt pain and whether the laws around animal use were needed. But with time, students seemed relieved to acknowledge that animals could feel, that humans were exerting power over animals in the lab, and we should be sure that the research was important. I encouraged students to find their comfort level, around caring for their animals, and trying hard to design experiments to use fewest animals and collect optimal data.
The research in my group uses frog and fish as experimental systems. The animals swim in large tanks and never have to worry about finding food, or poor-quality water. StilI, the ethical considerations have never diminished for me, and we try to make every experiment a useful one. The gratitude we must have for insights that animal experimentation provides to promote human health is deep and real.