Magnetic sense could lead to molecular manipulation

By understanding Magnetoreception - the ability of some animals to sense Earth’s magnetic field – a team of researchers is hoping to develop a new technique to control molecular processes.

The team – headed by scientists of Helmholtz Zentrum München and the Technical University of Munich – analysed zebrafish and medaka fish and measured brain activity during magnetic stimulation.

Professor Gil Gregor Westmeyer said: “To solve this question might not only satisfy neuroscientific curiosity but also lead to new molecular methods. Reverse-engineering the magnetoreceptor may lead to synthetic biology techniques for remotely controlling molecular processes with magnetic fields.”

To do this Westmeyer and his team wanted to establish an experimental model for magnetoreception. They focused on zebrafish, and the related medaka fish as they are well understood genetically addressed and casn be studied relatively easlily under the microscope. The researchers found that adult fish of both species change their swimming trajectories in response to a change in the direction of the Earth magnetic field introduced while carefully controlling for other variables. Interestingly, this effect also occurred in the absence of visible light ­– suggesting a photon-independent mechanism.

"In this model, we can now look for previously unidentified magnetoreceptor cells, which our behavioral experiments predicted would involve magnetic material", said co-first author of the paper in Nature Communications Ahne Myklatun, a graduate student in the Westmeyer laboratory. The researchers were able to show a similar magnetic field-dependent effect in young fish larvae - a distinct advantage for study as in their early developmental stages the fish are still almost transparent. This means imaging techniques to study the brain can be used during behavioral runs with changing magnetic fields.

"Magnetoreception is one of the few senses whose mechanism is not understood. The kind of multidisciplinary work we present here will ultimately lead to an understanding of the biophysical mechanism of magnetoreception and its underlying neuronal computation,” said Westmeyer. “These findings could also offer interesting approaches to engineer biological systems for the remote control of molecular processes with magnetic fields.”