In an experiment studying rainbow trout, researchers have just solved a long-running mystery of science: what makes migration possible.
The answer? Basically, migratory animals have magnets embedded in their friggin’ brains. Well, if not in their brains exactly, then woven into the fabric of their sensory tissue.
A breakthrough study published yesterday in the Proceedings of the National Academy of Sciences journal found that tiny iron-rich cells called magnetite embedded in the nasal passage of the rainbow trout were 100 times more powerful than previously thought, and essentially act as tiny compass needles inside the animal’s sensory system.
Fox News reports “These crystals lean back and forth like a sail in response to Earth’s weak magnetic field, and that the cells they are embedded in somehow convey their swaying movements to the brain. This is believed to confer trout and other migratory animals with a “magnetic sense” by which to judge direction.”
Lead researcher Michael Winklhofer said, “we show for the first time that the internal compass needle has a strong connection to the plasma membrane [or outer membrane] of the cell, which is important to realize an immediate sensing process.”
The magnetite cells are distributed sparsely and evenly—only one in 10,000 of the trout’s nasal cells is a “compass” cell—which made detecting them difficult in previous studies. Scientists have been trying to figure out whether magnetite cells could be powerful enough to play a part in migration for 30 years, and now thanks to this study’s technique of placing the trout’s cells inside a “rotating magnetic field” to separate the compass cells, we now understand the signal from these cells is strong enough to factor into animals’ sensory experience and explain their outsized directional abilities.
“It is quite possible that similar magnetite crystals are involved in detecting magnetic fields in numerous animals,” said Kenneth Lohmann, a leading biology professor.
It’s been a big couple weeks for scientific discoveries: first we confirm the existence of the Higgs boson, that makes matter as we know it comprehensible, and now we discover what makes migration possible. Go science!
[Image via Shutterstock]