文摘
Summary
Many animals use the Earth's geomagnetic field for orientation and navigation, but the neural mechanisms underlying that ability remain enigmatic [[1] and [2]]. Support for at least two avian magnetoreceptors exists, including magnetically activated photochemicals in the retina [[3] and [4]] and ferrimagnetic particles in the beak [[5] and [6]]. The possibility of a third magnetoreceptor in the inner ear lagena organs has been suggested [7]. The brain must process magnetic receptor information to derive constructs representing directional heading and geosurface location. Here, we used the c-Fos transcription factor, a marker for activated neurons [8], to discover where in the brain computations related to a specific set of magnetic field stimulations occur. We found that neural activations in discrete brain loci known to be involved in orientation, spatial memory, and navigation may constitute a major magnetoreception pathway in birds. We also found, through ablation studies, that much of the observed pathway appears to receive magnetic information from the pigeon lagena receptor organs.
