The possibility of using stem cells for drug screening was covered in more detail by Prof Chris Henderson from Columbia University New York. Prof Henderson has been a pioneer in drug screening in ALS: his work with the French biotechnology company, Trophos, which involved screening 50,000 drugs for a protective effect in rat motor neurones, formed the basis for the current clinical trial being performed by the company.
He went on to explain some of the challenges being encountered in developing a human stem cell drug screen – one of which is the fact that new motor neurones are being generated in the dish (a process called neurogenesis) over a prolonged period. If new motor neurones are constantly being born, it means that you do not have a stable baseline on which to test the effects of drugs. Prof Henderson outlined how they were getting around the problem and getting closer to a robust and reproducible model.