A recent research study – published in the journal “Nature” on February 22 has indicated that the ability to sense the magnetic field may be more widespread in various species of the animal kingdom than previously thought.
The study team, which includes researchers from the University of Manchester and the University of Leicester, also identified a molecule found in all living cell types that is capable of responding to a magnetic field.
This study contributes to significant advances in our understanding of how animals perceive and respond to magnetic fields in their environment. It could also provide an opportunity to develop new tools that can selectively stimulate the activity of biological cells, including human cells, using magnetic fields.
Magnetic field capture mechanism
According to the press release published by the University of Manchester, the study has shown that the molecule flavin and adenine dinucleotide (FAD) – present in all living cells – can transmit magnetic sensations to biological systems , if available in large quantities.
Scientists already know that species such as monarch butterflies, pigeons, turtles and other animals use the Earth’s magnetic field to travel long distances. However, this recent discovery could mean that molecules capable of sensing the Earth’s magnetic field are already present, to a greater or lesser extent, in all living things.
In this regard, Richard Baines , a neuroscientist and study leader at the University of Manchester, points out that “the mechanisms for perceiving the external world from seeing, hearing, touching, tasting and smelling are well known. In contrast, how animals perceive and responding to the magnetic field is still unknown.”
To perceive the magnetic field, the animals exploited the protein “cryptochrome”, known to be sensitive to light, Cytochrome (3d structure), iron-containing hemeprotein mainly responsible for the generation of ATP by electron transport, capable of performing oxidation and reduction .
The sixth sense
To understand this mysterious sense, scientists have used the fruit fly (Drosophila melanogaster) as a model to understand this mechanism. Despite the apparent difference, the fruit fly has a nervous system that works just like ours. Therefore, the fruit fly has been used – in countless studies – as an animal model that helps to understand human biology.
And discovering how animals perceive and receive the magnetic field – or as the sixth sense is called – is more difficult than discovering the other five senses. Neuroscientist Adam Bradlaugh , co-author of the study from the University of Manchester, points out that the reason for this is that the Earth’s magnetic field carries very little energy, in contrast to photons of light or sound waves perceived by the other senses, which transmit a large amount of energy relative to the magnetic field. To sense this tiny amount of magnetic field, the animals harnessed another protein known to be sensitive to light called Cryptochrome.
Tampering with other proteins
The absorption of light by the cryptochrome protein causes electrons to move within the protein, which generates an active form of this protein, assuming a distinct form from one of two states.
Here the role of the magnetic field comes into play, which affects the distribution of the ratio between these two states, which in turn is reflected in the period during which the ” cryptochrome” protein remains active.
The most startling discovery, which goes against our current understanding, Bradlaugh notes , was “the ability of cells to sense magnetic fields even with a small fraction of cryptochrome present.”
This means that even though cryptochrome lacks some of the protein domains that make it up as a whole, the carboxylate end of the protein (made up of just 52 amino acids) is the only one capable of sensing the Earth’s magnetic field.
Another alternative method
Bradlaugh adds that they showed “another possible way magnetic field sensing is involved. A flavin-adenine dinucleotide molecule found in all cells, when present in large enough quantities, can transmit magnetic sensing even if no fragments of the cryptochrome protein are present.”
These results are important for understanding the molecular mechanism that allows a cell to sense a magnetic field. It also helps us better understand how environmental factors, such as electromagnetic noise from communication networks, affect animals that rely on magnetism for survival.
The study was published in the journal Nature.