Despite the differences between animals and humans, there are similarities at the level of molecules, cells and organs, which is why studies on animals allow conclusions about what happens in the human organism – even if this extrapolation always has to be carefully considered. Nonetheless, animal experiments are currently the only alternative when it comes to certain research topics. For example, human brain tissue can usually only be studied from deceased individuals, because interfering with the brain of a living person entails risks that are generally not acceptable ethically for research purposes. On the other hand, artificially generated cell cultures – given the current state of the art – do not fully replicate the complexity of brain tissue in a living organism: A cell culture or organoid that reproduces the complex behavior of a vertebrate animal does not yet exist. Although cell cultures are very well suited for so-called drug screening, these setups essentially only register the extent to which a potential drug binds to disease-relevant proteins. They are thus at the very beginning of drug development. Which is to say that cell cultures are not suitable for investigating how a complex organism and its brain react to pharmaceutical substances. In view of this: Without animal studies, research and the development of therapies would be significantly limited, especially since promising findings from animal studies are generally a precondition for new medical procedures to be tested on humans. Fewer or no animal experiments mean – given the current state of the art – riskier studies on humans.

The fact is that animal studies have already contributed significantly to treatments. Animals studies paved, e. g., the way for so-called acetylcholinesterase inhibitors: for years, these drugs have been used in the treatment of Alzheimer’s disease. The latest Alzheimer’s drugs from the category of “amyloid antibodies” are also based, inter alia, on findings from animal studies. And in the case of Parkinson’s disease, the nowadays established therapy with the compound L-dopa (which is given to compensate for the lack of the neurotransmitter dopamine) was also preceded by studies on animals.

Studies on mice are part of our research on for example Alzheimer’s disease, because specific breeds with modified genome develop features of disease that are very similar to those of Alzheimer’s in humans.

We study rats especially in the context of our research on spinal cord injury.

In zebrafish, we study, e. g., how a nervous system regenerates after damage and to what extent gene mutations can lead to neurological diseases.

In fruit flies (Drosophila melanogaster), we study fundamental processes of brain development and neurodegeneration.

Studies on nematodes (Caenorhabditis elegans – “C. elegans” for short) – which grow to about 1 millimeter in length – give us insights, e. g., into microscopic aging processes that also occur in humans. This is relevant because many neurodegenerative diseases are age-related.