Brain As in humankind, the brain is the nerve-center of the wild Atlantic salmon, analyzing its environment, and providing a measured control over the organs of the wild salmon's body. As in most higher animals, a variety of hormones play an important role as chemical controllers of the salmon's life, affecting its behaviour, its migration, and even its change from a fresh water to saltwater creature and back. The brain analyzes information from the balance mechanisms which may sense magnetic fields, from the lateral line, from the eyes, from the olfactory rosettes, and from other sources, and in the blink of an eye allows the animal to react.