Scientists at Tufts University have created a three-dimensional brain tissue model that imitates brain function, a revolutionary tool that could be used to study the effects of illness, trauma and treatments on the brain. The model is a spongy, round scaffold made of silk proteins, a collagen-based gel and rat neurons. "They've been able to repeat the highest level of function of neurons. It's the best model I've seen," said nanoscience technology expert James Hickman. Details of the study appear in the Proceedings of the National Academy of Sciences.