Penn Researchers Engineer First System of Human Nerve-Cell Tissue (image) University of Pennsylvania School of Medicine Share Print E-Mail Caption Four individual human DRG neurons that survived for months in culture. Differing colors indicate different neuron-specific stains. Bottom: Center region of an engineered human nervous tissue construct showing stretch-grown axon bundles. Credit Douglas H. Smith, MD, University of Pennsylvania School of Medicine Usage Restrictions None Share Print E-Mail 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.