Can humans sense Earth’s magnetism?

Research suggests that a protein in the human retina might function as a magnetic sensor.

For animals that must navigate long distances, like sea turtles and migratory birds, the ability to sense Earth’s magnetic field is crucial. Although humans have been widely assumed not to have an innate magnetic sense, new research suggests that they might.

A study published in the June 21, 2011 issue of Nature Communications by faculty at the University of Massachusetts Medical School shows that a protein in the human retina can sense magnetic fields when implanted into fruit flies (Drosophila).

Image Credit: Penny Mayes

In many migratory animals, light-sensitive chemical reactions involve the flavoprotein called cryptochrome (CRY). These reactions are thought to play an important role in the ability to sense Earth’s magnetic field. In the case of fruit flies, previous studies have shown that the cryptochrome protein in these flies can function as a light-dependent magnetic sensor.

To test whether the human cryptochrome 2 protein (hCRY2) has a similar magnetic sensory ability, Steven Reppert – a physician and professor of neurobiology – and his team created a transgenic fruit fly lacking its native cryptochrome protein but expressing hCRY2 instead. Reppert’s group showed that these transgenic flies were able to sense and respond to an electric-coil-generated magnetic field and do so in a light-dependent manner.

Drosophila melanogaster. Image Credit: André Karwath

These findings demonstrate that hCRY2 has the molecular capability to function in a magnetic sensing system and may pave the way for new studies into human magnetoreception. Future studies could involve the effect of magnetic fields on visual function, rather than non-visual navigation.

Image Credit: Verino77

Bottom line: Steven Reppert and his team at the University of Massachusetts Medical School conducted studies with a transgenic fruit fly (Drosophila) expressing the human cryptochrome 2 protein (hCRY2). The transgenic flies responded to tests in a light-dependent manner, showing that hCRY2 has the capability to sense a magnetic field. Results of the study appear in the June 21, 2011 issue of Nature Communications.

Read more at ScienceDaily

Which bird migrates the farthest?

EarthSky