https://phys.org/news/2018-05-shark-electrical-sixth-tuned.html

Led by post-docs Nicholas W. Bellono, Ph.D. and Duncan B. Leitch, Ph.D., Dr. Julius' team showed that the shark's responses may be very different from the way the same organ reacts in skates, the flat, winged, evolutionary cousins of sharks and sting rays, and this may help explain why sharks appear to use electric fields strictly to locate prey while skates use them to find food, friends, and mates. They also showed how genes that encode for proteins called ion channels may control the shark's unique "sixth sense."

"Ion channels essentially make the nervous system tick. They play a major role in controlling how information flows through a nervous system. Mutations in ion channels can be devastating and have been linked to a variety of disorders, including cystic fibrosis and some forms of epilepsy, migraines, paralysis, blindness and deafness," said Nina Schor, M.D., Ph.D., deputy director at NIH's National Institute of Neurological Disorders and Stroke. "Studies like this highlight the role a single ion channel can play in any nervous system, shark, skate, or human."