Transcription Factor Protein (IMAGE) University of Pennsylvania School of Medicine Caption Time course of cell death for neurons which have been phototransfected with Elk-1 mRNA. In the first panel (O mins.) the lightning bolts and squares show the region of the dendrite into which the mRNA was phototransfected. By 180 mins clear indications of cell death in a cell soma attached to the phototransfected dendrite is observed (arrow) and by 420 minutes other cell somas attached to phototransfected dendrites are observed to be dying. Other cells whose dendrites are not phototrasfected are observed to be healthy in this image. Credit (Credit: Lindy Barrett, PhD and Jai Yoon Sul, PhD, University of Pennsylvania School of Medcine, and Nature Methods, June 2006 Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.