Stem cells: what can they do for you?

All tissues have populations of stem cells. However, not all tissues use these cells to regenerate with the same efficiency. Adult brains have plenty of stem cells. However, while they are very good at replacing glial cells (non-nerve brain cells), and especially the cells lost in diseases such as multiple sclerosis, they are very poor at replacing nerve cells lost in classic neurodegenerative diseases such as Alzheimer's disease. This talk will discuss this paradox at the heart of the brain.

We study how the founder cells of the foetus are specified in the early mouse embryo and how we can arrest their development and propagate them in culture. Characterising this process has enabled us to search for the equivalent state in human embryos. We will discuss the commonalities and divergence between mice and men at the level of the embryo and the implications and uses of developmentally unrestricted human embryonic stem cells.

Tissue stem cells are established during development and retained throughout adult life allowing the body to replace, restore and regenerate dead, damaged or diseased cells. However, stem cells often do not keep their promises: they lack clear identities, do not contribute to the regenerating organ or worse, some tissues can be maintained without them. I will discuss the very basic questions: What are stem cells? Where are they? And what are they actually good for?