Douglas H. Smith of the University of Pennsylvania School of Medicine and colleagues created a new way to engineer nerve structures in a petri dish.
Smith's group showed that they could grow axons by placing neurons from rat dorsal root ganglia (clusters of nerves just outside the spinal cord) on nutrient-filled plastic plates. Axons sprouted from the neurons on each plate and connected with neurons on the other plate. The plates were then slowly pulled apart over a series of days, aided by a precise computer-controlled motor system.