©M. Zernicka-Goetz
Ms. Schickl, researchers can grow tiny structures of the human brain in the laboratory. Should we fear what is to come?
No. In my opinion, the debate about human brain organoids is being unnecessarily inflated. It is guided by unrealistic Frankenstein-like fears that have little to do with the current and expected future state of research.
That is quite a harsh rejection of the criticism. Don’t you think that special protection of brain organoids is necessary for ethical reasons, even though they are similar to human brains?
A special protection of human cells cannot be ethically justified. It is not ethically relevant which species an entity belongs to, but which current, i.e. actually existing, abilities it possesses that give us a direct reason to take its needs into account. Human cells, cell structures, or brain organoids have no needs and are unlikely to ever have any. It is therefore more a question of intensively researching the use of human brain organoids as alternative methods to animal experiments.
“A special Protection more human cells is ethically not rightly somanufacture«
The National Academy of Sciences Leopoldina says that no regulation is currently necessary, but wants to monitor it. Are there criteria that can be used to determine when researchers should stop working?
Yes, as soon as suffering is caused. It would therefore be important to set stricter research limits: in animal experiments and also in interventions in the germ line, which includes egg cells and sperm. In animal experiments, the suffering caused is put into perspective by an ethically unjustified preference for the human species. With reproductive cloning, there is an international consensus that the health risk and possible suffering for the born human would be too great. In the case of germline intervention, however, the health risk remains similarly large – and it is now being considered internationally for future therapeutic use.
Researchers can create synthetic mouse and cynomolgus monkey embryos using stem cells. They do without typical sperm, egg cells and classic reproduction. How do you rate that?
The production of so-called embryoids has been the subject of intensive research for around ten years. Embryonic development is a biologically crucial phase of development that is poorly understood. Findings in this area can be important for both biology and medicine.
There is an argument about how science should label the products of this research. Many scientists reject the term “synthetic embryo”. Is language important in this context?
Yes, very important. When human embryos are protected in a country, it is not surprising that attempts are made not to label embryos as such. Because then the strict regulations do not apply. The same has already been attempted with parthenogenetic embryos, which are produced without sperm. In the case of embryoids – more precisely: stem cell-based embryos – it has now been argued, for example, that they are models and not embryos. Animals used in animal experiments are also often referred to as models by researchers. But that doesn’t change the fact that they are animals.
Embryoids from human stem cells represent stages of early embryonic development, presumably no human can develop from them. She and her colleagues argue about what protection they should have.
The protection of embryos in vitro (i.e. in the test tube) is essentially based on their potential to develop into humans. However, how far embryos can develop cannot be relevant for protection, otherwise embryos with chromosomal abnormalities that lead to miscarriage would not be protected. If developmental potential remains the decisive criterion for the protection of embryos, then consistently stem cell-based embryos must also be protected. However, the development potential is ethically highly controversial as a suitable criterion. If one is guided by current abilities, neither embryos produced by fertilization nor stem cell-based embryos are entitled to protection.
Do you raise doubts as to whether the concept of embryo protection is still on the right footing today?
The protection concept was never on the right footing. As science advances, this becomes more and more evident. Research on embryoids has shown that, contrary to previous assumptions, normal stem cells used for research are also capable of development. However, this means that the current protection of viable cells must be fundamentally reconsidered. For years scientists have been calling for the protection of embryos to be based not on potential abilities but on actual abilities, especially sentience, which is only present at a later stage of development.
Many people will be irritated by this change. For them, protecting an embryo is a matter of course because it cannot protect itself. What do you think?
This is based on the misconception that embryos are human from the moment of nuclear fusion. They are human, but not human yet.
From an ethical point of view, what has changed in the last few decades with regard to the right to protection for embryos?
Ethical positions are increasingly moving away from strong early protection of embryos towards gradualistic concepts in which protection increases with development. If one considers current abilities to be morally decisive, embryos in vitro can at most be given weak, weighable protection, for example based on consideration for feelings of piety in society.
You know the expert discussion well. Is there already a unanimous opinion?
Unfortunately, there are two fundamental positions that are quite irreconcilable when it comes to the question of embryo protection: those who already give embryos strong protection at an early stage and those who do not.