Japanese Researchers make the first-ever observation of live cells responding to a magnetic field
This is the first time that scientists have observed biological magnetoreception in live, unaltered cells in real-time
Birds and other animals are known to navigate their way using the Earth’s magnetic field (geomagnetic field). The so-called sixth sense for these animals is actually a process called magnetoreception. However, the exact functioning of the phenomenon was somewhat of a mystery until now. The leading theory explaining the process involves chemical reactions taking place at a cellular level through what’s called the radical pair mechanism.
Just like magnets can attract and repel electrons, the geomagnetic field influences animal behavior by inciting chemical reactions at the cellular level. When some molecules are excited by light, an electron can jump from one molecule to another and create two molecules with single electrons, known as a radical pair. This can create pairs of molecules with a single electron each, known as a radical pair.
Depending on the electrons having matching spin states or the opposites in these molecules — chemical reactions can occur within them slower or faster respectively. And since the magnetic field is known to influence electron spin states, the resulting chemical reactions can influence the animals’ behavior. For the past 50 years, scientists have identified specific proteins called cryptochromes — thought to be the molecules that undergo this radical pair mechanism.
“We’ve not modified or added anything to these cells. We think we have extremely strong evidence that we’ve observed a purely quantum mechanical process affecting chemical activity at the cellular level.”
~ Jonathan Woodward, Co-Lead Author of the study
Although biologists have identified that genetic interference with cryptochromes has caused a loss in the ability to navigate among fruit flies and cockroaches, but chemical reactions inside a living cell changing directly because of a magnetic field have never been measured before. Researchers from the University of Tokyo have now been able to do just that.
The team utilized the HeLa cells (human cervical cancer) to make the observations. Hela cells are the most commonly used cells in such trial studies. Their focus was on the cells’ flavin molecules — a group of molecules that glow naturally, or fluoresce, when exposed to blue light.
Excitement by blue light causes them to fluoresce or produce radical pairs and the fluorescence depends directly on the rate of reaction of radical pairs. Under a controlled environment, the cells fluoresced for about 40 seconds when exposed to blue light. When a magnetic field was passed over these illuminating cells with a time interval of 4 seconds, the fluorescence of the cells dropped by about 3.5% (animation above).
This dimming is being attributed by the scientists to the radical pair mechanism taking place. The magnetic field basically causes more of the radical pairs to have the same electron spin states with fewer flavin molecules available to emit light, and the cell’s flavin fluorescence dimmed till the magnetic field was taken away.
The experiment was conducted with a magnetic field strength of 25 millitesla — same strength as a fridge magnet, whereas the Earth’s magnetic field, comes in at a much weaker at 50 microtesla. The researchers did note that weaker magnetic fields can actually make the switching between the electron spin states much easier (low field effect), as compared to when there is no magnetic field at all.
Researchers will be conducting further studies to confirm their findings and also investigating the effect in other types of cells, the potential role of the cells’ health and surroundings, and testing candidate magnetic receptors.
Complete Research was published in the Journal Proceedings of the National Academy of Sciences.