They have Wolverine-like regeneration abilities–and can almost entirely regrow their spinal cords after damage. They also give scientists insight into some of the animal brain's most primal states. While working with week-old zebrafish larvae, a team of scientists decoded how the connections made by a network of neurons in the brainstem guide where the fish looks. They also created a simplified artificial circuit that can predict visual movement and activity in the animal's brain. This discovery sheds light on how the brain handles short-term memory and could lead to some new ways to treat eye movement disorders in humans.