Painful Art (image) Johns Hopkins Medicine Caption Creating scientific art, the word "pain" was traced by the researchers in magenta over nerve fibers glowing green. The nerves were genetically engineered to glow when they were activated by painful stimuli, like capsaicin. Hairs appear in yellow. Credit David Rini Usage Restrictions None 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.