Researchers at the University of Massachusetts Medical School have discovered that a protein expressed in the human retina has the capability of sensing magnetic fields when placed into fruit flies.
“It poses the question, ‘maybe we should rethink about this sixth sense,'” Steven Reppert, of the University of Massachusetts Medical School, told LiveScience. “It is thought to be very important for how animals migrate. Perhaps this protein is also fulfilling an important function for sensing magnetic fields in humans.”
The research, published in Nature Communications this week, found that fruit flies could sense and respond to an electric-coil-generated magnetic field when their native retina protein was replaced with a human retina protein called “human cryptochrome 2 protein (hCRY2).”
Previous studies had shown that the fruit flies’ native protein could function as a light-dependent magnetic sensor, but whether hCRY2 could function similarly was unknown.
Many birds and sea turtles use the Earth’s magnetic field to navigate during long migrations, but it was assumed that humans did not have a similar magnetic sense.
The research shows that hCRY2 has the capability to function in a magnetic sensing system, but there is currently no evidence that it is actually used by the human nervous system in this way.
“Additional research on magneto sensitivity in humans at the behavioral level, with particular emphasis on the influence of magnetic field on visual function, rather than non-visual navigation, would be informative,” wrote Reppert and his colleagues in the study.