Magnetic Particles Are Hiding In The Brain: Here’s Why

There's plenty of things that scientists are still trying to figure out about the brain, one of which is the mysterious presence of magnetic particles.

These particles' existence in the brain was first detected in the 1990s, but it has remained an unexplained quirk of the organ. For birds, magnetic sensors are invaluable in orientation. The function of these magnetic properties in humans are less clear.

Finding, Mapping The Brain's Magnetic Presence

In an attempt to shed some light on the mystery, researchers mapped the distribution of the magnetic particles in the brain for a study published in the journal Scientific Reports.

The team dissected and analyzed seven post-mortem human brains, confirming the existence of magnetic particles in all of them. The cerebellum and the brain stem were found with the highest concentration of particles, according to a report from Ludwig-Maximilian University of Munich.

Both of these regions are located in the lower back sections of the brain, which Live Science points out are more evolutionarily ancient than other parts of the organ.

The consistent distribution of the magnetic particles also indicates that they're most likely biological.

Stuart A. Gilder, study lead author and a professor at LMU's Department of Earth and Environmental Sciences, tells Live Science that he doesn't believe the particles come from pollution or the environment, since there wasn't a particularly high concentration near the olfactory bulb.

Another notable finding was the asymmetry in the distribution between the right and left hemispheres.

"The human brain exploits asymmetries in sensory responses for spatial orientation, and also for sound-source localization," Christoph Schmitz, study author and professor at LMU's Department of Neuroanatomy, explains.

While the asymmetric nature is in line with the existence of a magnetic sensor, Schmitz says that this sensor is likely too insensitive to be significantly useful in humans.

More Mysteries Left To Answer

While the recent research reveals a lot of key information about the brain's magnetic particles, there's still plenty left to learn.

For one, scientists still don't know the chemical nature of these particles.

"We assume that they are all made of magnetite (Fe3O4), but it is not yet possible to be sure," Gilder says.

Moving forward, the team is planning to characterize the properties of the magnetic particles as well as perform studies on whales. The large marine mammals regularly travel great distances between their feeding grounds, so the researchers are interested in seeing whether there are magnetic particles in their brains that are asymmetrically distributed too.