Resumen de What and where are the body's magnetometers?
Exactly how animals—and maybe humans—sense Earth's magnetic field is still a mystery. There are two rival explanations, one based on the mineral magnetite working as a mechanical sensor, and another based on the protein cryptochrome as a chemical sensor. Magnetite has turned up in many animal tissues and would provide the sensitivity necessary to respond to minute changes in Earth's field strength, as some animals appear to do. But magnetite could also be a metabolic byproduct. Cryptochrome has been found in the retina and, through a complex series of quantum chemical reactions, it could be a magnetically sensitive neural gatekeeper. But questions remain about its ability to provide a refined, precise compass.
