Sensor of Earth's Magnetic Field Found in Worm's Head

Posted on June 18, 2015

Scientists and engineers at The University of Texas at Austin have discovered that there is a sensor of the Earth's magnetic field inside the head of the worm C. elegans. This is the first discovery of this type of sensor in an animal. The diagram above shows where the TV antenna-like structure is located. It is found at the tip of the green-colored AFD neuron.

The researchers previously discovered the worm's ability to sense humidity. This led them to ask what else the worms might be able to sense. It is thought that other creatures known to navigate using Earth's magnetic field may also posses a similar magnetosensitive neuron. Many other species living in the soil also navigate vertically and may have magnetic detection.

Jon Pierce-Shimomura, assistant professor of neuroscience in the College of Natural Sciences and member of the research team, says in a statement, "Chances are that the same molecules will be used by cuter animals like butterflies and birds. This gives us a first foothold in understanding magnetosensation in other animals."

The researchers found that hungry worms placed in gelatin-filled tubes tend to move down. This is a strategy the worms might employ when they are hunting for food. However, hungry worms brought in from other parts of the world - including Hawaii, England and Australia - and placed in the gelatin-filled tubes didn't move down. The researchers found that the worms moved at a price angle to the magnetic field that would have corresponded to down back home. The Australian worms moved up in the tubes, which would have been the correct movement for down if the worm were still in Australia and not in a lab in Texas. The researchers found each worm's magnetic field sensor is finely tuned to its local environment.

A research paper on the worm's sensor is published here in the journal, eLife.

ANIMALS
WORMS