Pigeons sense Earth’s magnetic field in an entirely new way

Amazing stuff! When will humans be able to do some magnetoreception?

"... It's now proved that a wide variety of animals detect magnetic fields. This sensory ability helps birds and insects migrate and turtles remember the locations of rich feeding areas.

There are two widely discussed mechanisms.

One is better established: Light-sensitive proteins, called cryptochromes, inside the retina have so-called quantum spin states that respond to magnetic fields, revealing the direction of a field and giving the animals a visual indication of which way is north or south.

The other mechanism is less well demonstrated. Tiny iron-rich crystals, comprised of the mineral magnetite, rotate in the magnetic fields in ways that could stimulate cellular receptors, providing a signal to nerves that could be interpreted to understand the direction of magnetic field lines. Some scientists claim these crystals exist near nerves in the noses of trout and birds’ beaks, but their existence remains controversial. ..."

"... observed robust activation in a brain region called the vestibular nucleus, which is connected to the inner ear. Genetic analysis of inner ear tissue revealed cells with highly sensitive electric sensors. ..."

From the abstract:

"How animals detect the Earth’s magnetic field remains a mystery in sensory biology. Despite extensive behavioral evidence, the neural circuitry and molecular mechanisms responsible for magnetic sensing remain elusive.

Adopting an unbiased approach we employ whole brain activity mapping, tissue clearing, and light sheet microscopy to identify neuronal populations activated by magnetic stimuli in the pigeon (Columba livia).

We demonstrate robust, light-independent bilateral neuronal activation in the medial vestibular nuclei and the caudal mesopallium.

Single-cell RNA sequencing of the semicircular cristae revealed specialized type II hair cells that express the molecular machinery necessary for the detection of magnetic stimuli by electromagnetic induction.

Our data supports a model whereby electro-magnetic input from the semicircular canals activates a vestibular-mesopallial circuit within the pigeon brain."

Pigeons sense Earth’s magnetic field in an entirely new way | Science | AAAS "Specialized hair cells pick electric currents induced by magnetism"

Elusive sensory organ: Pigeons detect magnetic fields through inner ear (original news release)

A global screen for magnetically induced neuronal activity in the pigeon brain (no public access)