This animation shows is a 'broken' electrical circuit at the beginning, one in which the electrical impulses (the light) travels from left to right and then stops. Stem cells were placed at the 'break' (the location where the electrical impulse goes dark) along with growth factors to attempt to get the electrical circuit to reform. When done, the electrical impulses now travel the whole way.
http://www.callanproductions.com/Mayr/JH_Nerves_03_Avid.mov
http://www.callanproductions.com/Mayr/JH_Nerves_03_PhotoJpeg.mov
Animation courtesy of Johns Hopkins Project Restore
