Neurons from stem cells: preventing an identity crisis

It is now possible to grow stem cells from a wide variety of tissues. Some of these cells have been shown to differentiate Into presumptive neurons in vitro, or after transplantation Into the developing or adult brain. When stem cells derived directly from the brain are induced to differentiate, there is a high probability that some of the resulting cells will be neurons. However, when stem cells from one tissue (for example, bone marrow or skin) take on the phenotype of another (for example, brain), rigorous criteria are required to define neurons. The arn of this review is to discuss the various techniques that are used to Identify a cell as a neuron.