Human skin cells can be reprogrammed into neural cells that form synapses with neurons in severed spinal cords in rats.

A team led by Paul Lu and Mark Tuszynski at the University of California San Diego in La Jolla took skin fibroblasts from an 86-year-old man, converted them in culture into induced pluripotent stem cells (iPS cells) and then into neural stem cells, and grafted these cells into two-week-old immunodeficient rats whose spinal cords were damaged at the neck. Three months later, the stem cells had grown into neurons that projected axons along the whole length of the rat spinal cord, even extending into the brain. Unlike similar experiments with neurons derived from embryonic stem cells, these iPS-cell-derived neurons did not restore movement in the rats' limbs, perhaps as a result of scar tissue that formed at the injury site.

Neuron http://doi.org/t36 (2014)