EXCHANGE: Worms attracting interest in magnetic research

NORMAL, Ill. (AP) - A tiny worm may hold important clues about how animals use magnetic fields.

"It's one of the few remaining frontiers in neurobiology," said Andres Vidal-Gadea, assistant professor of molecular neuroethology at Illinois State University. "We have the potential at ISU to be the first to figure out how animals do this."

People tend to think of magnetic location as something used by only a few animals, such as migrating birds, said Vidal-Gadea, but "magnetic orientation is very common."

It's found in sea turtles, salmon, insects and, yes, even worms.

"People have known for a long time that animals can detect magnetic fields," but finding out how they do it is "kind of a needle in a haystack," he said.

Large animals can have millions of neurons in their brains and only one might be involved in detecting magnetic fields. But the tiny worms - transparent nematodes - that Vidal-Gadea studies in his lab have only 300 neurons. That makes the "haystack" much smaller and more manageable.

"I tell my students, 'You probably know 300 friends on Facebook you can track and know what they're doing," said Vidal-Gadea, so it's not difficult to track 300 neurons in a worm called C. elegans that he has been studying for years. Much of the research in his lab involves muscular dystrophy.

Vidal-Gadea already knows C. elegans can detect magnetic fields.

To answer the threshold question, he put a magnet near the millimeter-long worms "to see what happens" and "found they moved toward the magnet."

The $638,000 grant he received from the National Science Foundation will enable him to delve deeper into the questions, using graduate and undergraduate students.

One of those students is Chance Bainbridge of Macomb, a doctoral student in neuroscience and physiology who has been working with Vidal-Gadea for four years.

Bainbridge studies worm behavior.

"Believe it or not, worms have more than one behavior. They don't just wiggle," he said. "They're not going to write poetry or do math, but they can learn that a hot temperature is bad."

To find out which gene or gene plays a role in magnetic location, researchers "turn off" one gene at a time.

"It's kind of like you try to start your car and you pull something out and it doesn't start," Bainbridge explained.

Vidal-Gadea said one way animals, including bacteria, use magnetic location is by building their own "compass."

Like oysters create a pearl, bacteria can ingest iron and turn it into iron "pearls" that align with the magnetic field, he said.

"People have found these pearls in all kinds of animals with this behavior," said Vidal-Gadea. "We found our worms actually have these particles, too."

It creates a sort of internal compass, he said, "like having someone pulling on your arm toward north all the time."

Bainbridge has seen the worms start turning north, then turn another direction.

"It's almost like they check a compass," said Bainbridge. "We think they reset or recalibrate their compass regularly."

Humans have magnetic particles in our tissues, too, said Vidal-Gadea.

Studies of whether humans can orient with magnetic fields have produced mixed results, he said.

"The story's not over on that," said Vidal-Gadea.

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Source: The (Bloomington) Pantagraph, https://bit.ly/2Bc0D3m

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Information from: The Pantagraph, http://www.pantagraph.com