Nerve "Sympathy"

[Proteus]

Is it possible for the stimulation of one nerve to cause a reaction in another nerve not connected to it? I can't give any examples, but I think I've felt such sensations before. It could be that the places in question were actually part of the same nerve, though, but is it possible for this to happen for different nerve branchings?

[Mr Skeptic]

I've had a similar sensation, for example where pain in a lower molar translated to me also feeling pain in an upper molar directly above it. Keep in mind that the brain has a map of our body, with portions of the brain responsible for one part right next to each other. This might be responsible?

[Proteus]

Interesting. I wonder if this phenomenon has a name.

 

Yes, I think this is the most likely explanation. After all, if it did spread from one nerve to another, the entire nerve would be affected. On the other hand, in the brain it may easily spread from two adjacent areas even if the parts they represent are wide apart. For example, the eyes lie above the thumb. The upper and lower molars lie adjacent to one another in the brain whereas in the body their nerve endings are disjunct.

 

Where the molars on the same side, and where they on the back of the mouth? The left and right teeth are quite wide apart, and I'd assume the upper and lower teeth are separate (though adjoining), so if it was a cerebral effect it would have to be.

 

But how far can such reactions go?

 

Also, perhaps there is at least sometimes some peripheral element to it. A spinal disc herniation may cause numbness in the toes, for example. But in this case, that's because the same nerves transmitting to the toes are affected. Still, are there any other examples in which separate nerves react with a sensation to the same stimulus?