Not even the most trained champion can survive as long under water as marine mammals. Our brain needs a constant supply of oxygen, especially during physical exercise, in stark contrast to what happens, for example, to some seals that manage to stay under the Antarctic ice to look for food, up to 90 minutes, staying active and mentally perfect all the time. What is their secret? According to a study conducted at the University of California, Santa Cruz, some animals, including dolphins, whales and sea otters, appear to have high levels of complex proteins in their brains. And it is precisely these neuroglobins and cytoglobins that would protect brain structures from hypoxic states (lack of oxygen). The cytoglobins would in fact be able to efficiently transport oxygen into the brain even when circulating oxygen levels are extremely low, while neuroglobins seem to be able to block the formation of destructive free radicals. It is not yet clear whether the high levels of these proteins found in some species are already present at birth or their production is stimulated by behavior and the environment. In any case, the quantities of oxygen transport proteins seem to be inducible anyway. This mechanism could also be used in humans to minimize brain damage due to diseases that reduce the blood supply to the brain.