If nerves are basically just signal-carrying wires, why cant they just be reconnected with copper wire in the case of injury?



Edit: Or gold. Or something else electrically conductive but biologically safe.

In: Biology

Safest answer is probably that copper wires wouldn’t really be able to flex or move as the body does so using them as a replacement wouldn’t work. Not to mention the actual biological repercussions of putting copper wires into the body. If you can even shave copper down to the size it ywould need to be to become a nerve.

The signals they transmit are electrochemical. A neuron that gets triggered releases ions on one side (near the next neuron). That triggers that neuron, which sends the signal on, so on and so forth.

So it’s not just an electrical current that you can propagate with a wire. There’s a biological component to it.

Well I can’t say if it would actually work or not, I don’t know but I can imagine a few ways it can fail. I think the most important reason is that copper is toxic to humans. Don’t shoot up copper kids!

1) The signals that nerves conduct are *electrical*, but they’re not *electricity.* It’s not electrons hopping from atom to atom in the direction of higher reduction potential; neutons move *ions* around. They move “action potentials”, where the positively-charged side of the cell membrane quickly switches to being negatively-charged and vice-versa by dumping a bunch of ions. Not only can ions not jump from metal atom to metal atom because they’re as big as the metal atoms themselves, but it takes a whole bunch of biological machinery to maintain, e.g. the sodium-potassium pump to move ions back into the right position. A passive wire doesn’t do any of that.

2) Nerve bundles can have millions of different nerve fibers all going to slightly different places. Not only would the copper wire have to be extraordinarily thin, but how would you be able to tell *exactly* which nerve cell on either side of the the split you’re trying to sew back up it should connect to, so as not to accidentally reroute the signal to somewhere it’s not supposed to go?

3) Copper is not completely nontoxic although it is necessary in trace amounts for a few proteins. But the copper wire would most likely start leaching copper ions that not only might interfere with the ion electrical signal, but would cause a buildup of copper in bodily tissues causing more health problems than it solves.