Originally Posted by glenntaj

--it's been posited for a while now that trophic changes to neurons that are constantly being signaled to produce pain sensations may change chemically in a way that makes them easier to excite than previously, and then they may signal pain whereas before an equal stimulus would not cause them to fire in that way. In other words, these neurons become "conditioned" to fire to lower levels of stimulus, which would normally not be perceived as painful at all.

On the sensory level, neurologists refer to this as allodynia--sensations of pain from normally non-painful stimuli.

A number of the anti-epileptics--gabapentin (Neurontin) and pregabalin (Lyrica) specifically--are thought to work by upregulating the action of GABA, an inhibitory neurotransmitter, so that these nerve do not fire as such low stimulus levels.

It would be a great thing, though, if research provides us with a way to "re-train" such overly excitable neurons.