ANIMAL RESEARCH: THE GOOD, THE BAD, AND THE ALTERNATIVES
Animal research is a very controversial topic that has been generating heated arguments and debates all around the world over the past few decades. Recently, there appears to be an overwhelming growth in animal right groups all over the world. Most of these groups don’t just support animal welfare, but they demand a ban on any kind of use of animals in research. At the same time, more and more pro-testing groups that support the humane use of animals in research have been forming – these proponents argue and recognize the essential role that animal research has played in medical advancements and breakthroughs throughout the years.
Imagine for a second, a world where animal research is banned. First of all, medical progress would come to a standstill, with a variety of major setbacks in developing treatments for devastating diseases, including neurodegenerative disorders such as Multiple Sclerosis, Parkinson’s disease, and Huntington`s disease. Yes, we would still be able to use non-invasive techniques on humans (ie Magnetic Resonance Imaging – MRI) and in vitro “test tube” experiments, but will that be adequate? At least in my field of research, Neuroscience, in vitro (Latin for “in glass”) studies are not very representative of the complexity of the human brain. This is a general disadvantage of in vitro studies; in most cases, the natural environment of the cells or the tissue cannot be easily replicated in a petri dish. Of course, in vitro experiments are useful in certain cases and there are various applications for them, but they don’t emulate the environment and complexity of a living “in vivo” tissue (no surrounding tissues, no blood supply, nutrients etc).
The truth of the matter is that the majority, if not all scientists and researchers acknowledge the difficult ethical issues that arise from animal research. To my knowledge there is no scientist that enjoys using animals in research, as it’s been insinuated by various animal extremists. This type of research is demanding, time-consuming, laborious and very expensive. Animals need to be housed, fed, constantly monitored and taken care of by specially trained animal welfare technicians and veterinarians, especially since stressed animals tend not to provide the best experimental results. Regardless, it is necessary, at least for the time being, to rely on such studies to understand how our body functions and to develop new effective drugs for diseases.
The most important question we need to address as researchers and scientists is the following: Why use animal models in research? Animal models can provide a great tool to learn about certain diseases, especially in regards to how they progresses in time and how they can be diagnosed. They also allow us to find new ways to treat diseases without endangering human lives in the process.
What animal activists fail to understand, in my opinion, is that we researchers appreciate the past and present contribution of animals to improving human health, helping cure diseases and saving lives. We take animal welfare very seriously and we are committed to the humane treatment of the animals under our care. Investigators are required to carefully design research projects and protocols, while taking into account the Three Rs (Reduction, Replacement and Refinement) [1]. The Three Rs represent widely accepted ethical principles that are taken into account when designing a research project involving animals. They promote the replacement of animals where possible and the reduction of the overall number of animals used in the other cases through refinement of the techniques and procedures employed. These principles also ensure there is a continuous refinement of the established protocols in order to provide better conditions and care for the animals.
One of the main arguments used by animal activists against the use of animal models in research is the fact that in many cases, the results obtained from animal research and treatments that worked in animals were not successful in clinical trials with humans and vice versa. [2] The fact of the matter is that no animal model can completely reproduce a human disease or a human organ simply because of the biological differences between the different species. However, by choosing the appropriate model you can get a relatively good representation and therefore more accurate and relevant results. This does not necessarily mean that we have never learned anything or provided safe and successful treatments based on animal research. On the contrary, there are countless examples that provide evidence on the merit of such practices. The development of several vaccines we use today is largely based on animal research, like the human papilloma virus (HPV) vaccine [3], the whooping cough and the polio vaccine; as well as the discovery of insulin, the development of organ transplant techniques [4] and anti-transplant rejection medication [5].
Another important argument made by animal activist is that there are several alternative methods to conduct research and gather the results necessary for medical advancements. These alternative methods, however, cannot replace animal research just yet. Some of these methods include imaging techniques, such as MRI and functional MRI (fMRI) scanning, in vitro testing, micro-dosing and computer models.
Imaging techniques like MRI and fMRI scanning allow us to see areas of the brain “light up” under different conditions giving us important information about how the brain works at a large-scale. Nevertheless, imaging techniques have their limitations. The resolution is quite low, which means that you cannot see individual brain cells, but rather whole areas that could contain thousands of different types of brain cells. In order to study brain disorders, it is important to know what cell types are affected and how, which is not possible with the current non-invasive imaging technology. Imaging techniques can provide invaluable information, but once again animal research is needed to understand diseases at the cellular and molecular level.
In vitro testing is based on the use of tissues and cells, a major source of which was and continues to be animals. Immortalized cell lines (that are preserved for many years and used over and over) are not always representative of the physiological functions of cells that are in their normal environment, the body. Even though there are applications for these immortalized cells, using “fresh” cells will yield results that will more closely represent what really happens in the body. We could possibly use human cells to address the need for these “fresh” cells, however, there are tissues and cells that are much more difficult to obtain from humans. One good example is brain cells. Would anyone be willing to go through unnecessary and extremely risky procedures to donate brain cells to science? Probably not. This brings us back to the use of animals to obtain the necessary cells to even conduct in vitro testing.
Micro-dosing (Phase-0 microdosing trials) is a new technique used to study the effect of drugs in humans by administrating very small doses, as the name of the technique suggests. The idea behind micro-dosing is the administration of doses so low that it is unlikely they will cause a large-scale response (throughout the body), but instead cause a small localized response that can be observed and studied. However, this technique has a few limitations. Since it only studies small doses of a drug, it cannot effectively predict the consequences of administrating a higher pharmacological dose. [6] Future studies may be able to exemplify whether the body responds the same to “micro-doses” and pharmacological “therapeutic” doses of a particular compound. Generally, micro-dosing seems to be a very promising tool that might potentially replace the use of some animals in drug testing trials in the upcoming years.
To quote Professor Stephen Hawking – “Computers can do amazing things. But even the most powerful computers can’t replace animal experiments in medical research.” (Quoted by Seriously Ill for Medical Research in 1996). Computers might not be fast or powerful enough yet to simulate and reflect all aspects human physiology, but they are closer than ever. New advancements in the fields of computer science and engineering are making projects like the “Human Brain Project” [7] (human brain simulation) possible. It is important to note that computers can’t possibly replace the study of a live brain, since we don’t understand its complexity to a point where we are able to produce programs that can represent brain function effectively. Computer model simulations could, however, contribute to the optimization of experimental protocols, and thus result in the reduction of animals required for research.
Research is always evolving, improving and progressing. It is possible that in the future we might not need to use animals for research proposes as better, less expensive and time consuming methods may be available. Unfortunately, we are still not at the stage where animal research is obsolete. I do believe that scientists can and should devote the time and effort to adopt such techniques when possible, as well as help develop and refine new techniques and procedures that will help minimize unnecessary use of animals. Finally, it is important to communicate to the general public how animal research is conducted and how carefully animal welfare is being addressed by scientists, as well as the measures that are in place to protect and care for the animals.
References:
1. Russell, W.M.S. and Burch, R.L. The Principles of Humane Experimental Technique. 1959.
2. Perel, P., et al., Comparison of treatment effects between animal experiments and clinical trials: systematic review. BMJ, 2007. 334(7586): p. 197.
3. Peng, S., et al., Development of a DNA vaccine targeting human papillomavirus type 16 oncoprotein E6. J Virol, 2004. 78(16): p. 8468-76.
4. Moore. F.D Give and Take: the Development of Tissue Transplantation. 1964, New York: Saunders.
5. Discoveries in Pharmacology, ed. Parnum, M.J. and Bruinvels, J. Vol. vol 3. 1986, Amsterdam: Elsevier.
6. Garner, R.C. and G. Lappin, The phase 0 microdosing concept. Br J Clin Pharmacol, 2006. 61(4): p. 367-70.
7. Human Brain Project, H.B. 2013; Available from: https://www.humanbrainproject.eu/