The scientists screened over 100 potential toxins to find one protein from Peruvian green velvet tarantula that blocks pain transmitting neurons.

"The beauty of the system is we can also screen engineered toxins not found in nature, and identify higher-potency and more specific molecular variants that lack deleterious effects on essential nerve functions,'' Michael Nitabach, associate professor of cellular and molecular physiology and of genetics, and senior author of the paper.