Questa volta abbiamo cercato una curiosità scientifica:
Just learning about electromagnetism, and I’m curious whether anything is known about magnetic fields generated during action potentials.
Do charged molecules interact/move with magnetic fields for functional purposes in our body?
Further, do any human cells use magnetic interactions to communicate? Do any other animals use magnetism to communicate? Is there a magnetic-gated channel perhaps, similar to a voltage-gated channel?
Thanks!
Ed ecco le risposte degli esperti:
Yes action potentials induce magnetic fields, as you’d expect with Maxwell’s equations. No we don’t communicate with them, they’re pathetically weak. Some animals are receptive to Earth’s magnetic field, but through a different mechanism. If there are receptors, we haven’t found them.
The only reason it ever comes up really is transcranial magnetic stimulation, and magnetoencephalography. But they’re not the most robust techniques.
I cant speak to their generation but I worked on a few mechanisms for their perception if magnetism, which would imply small amounts of generation.
Back when I was on a team researching this there were three main magnetic perception mechanisms: inductive, mechanical, and radical pair.
Inductive is how sharks perceive the electromagnetism produces by the neurons of other fish. They have fluid filled, tubular organs that activate neurons when an inductive current is generated inside the organ. They’ll sweep their heads when swimming in order to use these.
Mechanical is how some species of bird perceive magnetism. A magnetic compound will sit on an activation gate of a neuron. When the compound reacts to a field, it pulls the gate open and triggers a aynatpic response through the normal neuronal mechanisms.
I worked on the radical pair mechanism five years ago, and it’s the most implausible but still seemed to work back then. The idea was a highly stabilized compound would divide into a radical pair when it is exposed to light. That compound would be prevented from reforming by one of the electrons in the radical having its spin state changed to the same state as its pair. Since a pair must have opposing spin states, this would momentarily prevent reformation and somehow cause a synaptic response. I left the lab five years ago so I dont know what the current science on this stuff actually is.
So to answer your question, yeah they produce electromagnetism, the Inductive mechanism of perception depends on it.
I’m on mobile so I probably wont fix my typos.
Edit: fixed a typo, but not the first one. I’m leaving it.
The problem with magnetism is that all you have to work with are dipoles. That makes the interaction strength fall off with a 1/r^3 ratio.
This makes it more efficient to communicate using electric fields than magnetic fields, as ions are electric monopoles and easy to produce.
This doesn’t motivate the use of magnetism in living things, especially because producing magnetic field usually comes hand in hand with an electric field. This provide an evolutionary pathway towards the superior “technology”, so it would be unexpected to find a living process that got stuck into using magnetism.
The problem with magnetism is that all you have to work with are dipoles. That makes the interaction strength fall off with a 1/r^3 ratio.
This makes it more efficient to communicate using electric fields than magnetic fields, as ions are electric monopoles and easy to produce.
This doesn’t motivate the use of magnetism in living things, especially because producing magnetic field usually comes hand in hand with an electric field. This provide an evolutionary pathway towards the superior “technology”, so it would be unexpected to find a living process that got stuck into using magnetism.