Many animals have been known to take advantage of the Earth’s magnetic field, often for migration (sometimes even for more rudimentary functions). Until recently, little was known about how animals are able to sense this magnetic field. Researchers at University of Texas at Austin have discovered an internal structure in the brain of a worm, C. elegans, which allows it to orient itself to the Earth’s magnetic field. This is the first discovery of an explicit structure which senses the Earth’s magnetic field in an animal.
The study of these worms began with a simple observation: worms that are hungry tend to move down, likely as a way of searching for food. Worm specimens everywhere from Australia to England were gathered in Texas. In the Texas lab, not all worms moved down when hungry. Researchers discovered that the worms moved at the exact angle that would have been down in their native environment according to the Earth’s magnetic field. They then used calcium imaging to identify the precise neuron which contained the magnetic sensing structure. They also found that when this neuron was broken, the worms no longer oriented themselves like normal worms.
While the magnetic sensing structure has been discovered, nothing is yet known about how it actually senses the magnetic field and translates that information for the brain. Even so, this discovery has opened up a window into much more exciting work regarding animals and their sensitivity to Earth’s magnetic field.
Acknowledgments: Many thanks to Amy I.Gilson (Department of Chemistry and Chemical Biology, Harvard University) and Elizabeth Lamkin (Program in Neuroscience, Harvard University) for providing their expertise and commentary on the topic.
Managing Correspondent: Tomo Lazovich
Original article: – eLife