While the phrase "follow your nose" has been around a long time,
scientists are beginning to find that it may actually be true -- for
animals anyway. They have found cells in the snout of a trout that
respond to magnetism. This could be the explanation of how animals are
able to orient themselves, even when it is dark or cloudy.
Decades ago research showed that electrical activity of the nerves that carry information from the nose of the fishes to the brain were affected by magnetic fields. Back then the standard method of tissue analysis would be to grind up the tissues to get a closer look at the cells. New scientific methods have allowed researchers to take up the subject again. Now they are able to isolate specific cells and remove them for study.
When the cells were exposed to magnetic fields about one in 10,000 would spin with the same frequency. These same cells also glowed brightly under the light of the microscope, making them easier to identify. A closer look showed that there appeared to be a tiny crystal attached to the inner membrane of the cells. These crystals seem to be made of magnetite, an iron-rich mineral.
There is no doubt now that migratory birds and fish have a magnetic sense, the problem remains that scientist still don't know how it works. However, their hypothesis at this point is that the cells may be the trigger that sends directional information to the brain.
This finding is likely to lead to wider-ranging research, including into the idea that humans may carry some of these cells as remnants from their hunter-gatherer past. Should this be true there could be implications as to how the magnetic fields of power lines may affect us. New research along these lines may also open a way to restore missing senses, such as sight, smell, and hearing, to those impaired by their loss.
It is clear that the animal kingdom still has a lot to teach us.
Source: Discovery News