From ScienceDaily: "researchers were able to generate functionally mature motor neurons from induced pluripotent stem (iPS) cells, which are engineered from adult somatic cells and can differentiate into most other cell types. A potential new source of motor neurons that does not require human eggs or embryos could be an enormous boon to research into conditions such as amyotrophic lateral sclerosis (ALS) and spinal cord injury and could open the door to eventual treatments. ... To our knowledge, our results present the first demonstration of the electrical activity of iPS-derived neurons and further suggest the feasibility of using these cells to explore how changes in motor neuron activity contributes to the degeneration of these cells underlying these disorders. ... [the team] used skin fibroblasts and reprogrammed them back into an embryonic state, with the ability to differentiate into any cell type in the human body. They then took those cells and differentiated them into motor neurons."