Scientists have proven a 60-year-old theory about how nerve signals are transmitted through the body at varying speeds as electrical impulses. Researchers tested how signals are transmitted through nerve fibers, enabling movement and sensation. They found that the longer the insulating myelin layer between gaps in the fibers, called nodes, the faster the signals are conducted. This validates a theory first proposed by Nobel laureate Sir Andrew Huxley. The study also confirmed that the protein periaxin regulates the length of myelin layers and provides insight into nerve development and regeneration.