No one wants living beings to suffer, and no one wants to see images depicting the suffering of others – whether humans or animals. That is why the pictures of laboratory animals broadcast by the German television programme stern TV in September 2014 and again just recently in January 2015 are disturbing. However, the truth of the matter is that they fail to broach one very important subject: What kind of images would we be seeing if we were to abstain from acquiring the knowledge we need to save lives and ease pain?
The history of science is abundant with proof that researching the very mechanisms that make life possible has already resulted in a vast number of strategies with which we can prophylactically prevent or cure diseases or favourably influence their progression. The average human life expectancy has nearly doubled over the course of the past one hundred years alone. Diseases such as the plague, which wiped out one-third of Europe’s population in the Middle Ages, hardly play a role anymore in today’s world.
Yet new diseases are appearing in their stead. Due to increased life expectancy, for example, more and more people are suffering from degenerative conditions of the nervous system such as Alzheimer’s and Parkinson’s disease, which can drastically reduce the quality of life of the patients and their families. In order to prevent or at least alleviate this type of human suffering, researchers are seeking new treatment approaches.
One example of such an approach is a therapy that uses deep brain stimulation to treat the movement disorders associated with Parkinson’s. About a decade ago, researchers succeeded in simulating an accelerated form of Parkinson’s disease in rhesus monkeys, thus allowing the scientists to study the underlying causes of the movement disorder in great depth. Thanks to these findings it is now possible to all but completely eliminate the motor disturbances by stimulating a brain structure using implantable electrodes. Several hundred thousand patients are already benefitting from this treatment today.
But they are not yet cured, because the causes of these degenerative processes remain unknown and untreatable. Unfortunately, the same applies to all other degenerative diseases. That is why intensive research is being conducted using animals models that are also suitable for these types of degenerative processes. Developing effective treatment approaches for the psychiatric disorders schizophrenia, depression and autism is proving much more difficult, due to the fact that there are no animal models that would be suitable for exploring these complex illnesses.
Therefore, all that researchers can do for now is study the mechanisms of the higher cognitive functions that are impaired in patients suffering from these diseases. This requires working with non-human primates, as they are the only beings in which these respective functions are developed. That is why medical scientists all over the world use rhesus monkeys to explore the underlying neuronal mechanisms of complex brain functions. These animals are trained to solve complex tasks while their brain activity is being measured in a pain-free manner. These types of tests are also conducted at the Max Planck Society, because they are indispensable for important areas of brain research.
This indispensability along with the respective ethical justification is reflected in European and national legislation. Experiments on non-human primates are thoroughly reviewed using scientific and ethical criteria, and any authorisation to conduct such tests is subject to particularly strict requirements, the adherence to which is monitored by the authorities. In addition to ethical considerations, another important criterion used for assessing the necessity and appropriateness of animal tests are the sober facts and figures.
Only 0.3 per cent of all animals that are sacrificed for human needs are used for research purposes. The majority of these laboratory animals are rodents; non-human primates make up only 0.05 per cent. And that number includes the primate experiments that are indispensable for developing effective drugs and vaccines against epidemics such as AIDS and Ebola.