Pigeons are famous for their ability to travel long distances and still find their way home. The cause is in the liver.
The cells, called macrophagesthey help to break down aging red blood cells, and by accumulating this task, they accumulate iron. According to researchers, iron can give cells quantum properties that allow them to respond to magnetic fields.
According to , when these cells were removed, the birds had difficulty finding their way back home.
In new, published last week in Sciencethe team of scientists examined several parts of the pigeon’s body that had been considered candidates, including the eyes, beak and brain.
“We did not expect immune cells to act as sensors of magnetic fields. Our results reveal a previously unknown mechanism of magnetic perception in animals”, says the study’s lead author, Christian Kurts.
Techniques such as vibrating sample magnetometry e magnetic cell separation to measure properties in different fabrics.
“We had some clues that the liver and spleen have magnetic properties, as they break down red blood cells and, therefore, store a lot of iron in the body”, explained the first author of the study, Clivia Lisowski.
O liver stood out of all other fabrics tested, presenting the highest concentration of iron.
To find out whether these cells really influence pigeon navigation, the researchers carried out several orientation experiments with pigeons trained to return to their aviary from distances greater than 20 kilometers.
When the liver macrophages were removed, the birds lost their sense of direction on cloudy days, when the sun was not visible. On sunny days, they continued to return home successfully.
The results suggest that pigeons use several navigation systems and that magnetic detection becomes important when visual guidance provided by the sun is not available.
Next, the researchers sought to understand how information from the liver could be transmitted to the brain. Through electron microscopydiscovered that iron-rich macrophages are found close to nerve fibers.
This arrangement could constitute a pathway through which magnetic information is transmitted to the nervous system.
The discovery brings together several biological processesincluding iron metabolism and communication between the immune and nervous systems, in a possible explanation for how animals orient themselves when using the Earth’s magnetic field.
Finally, animals like sharks are able to orient themselves without relying on light, raising the possibility that similar mechanisms may exist in other species.
