I think I’ve mentioned in the past some of my ideas that chronic pain might involve sensory neurons in the body “learning” pain. An observed behavior of neurons is that they sit there, receiving electrical signals (from other neurons), but they don’t pass on their own electrical signals until a threshold is reached. So a certain neuron might get 25 “jolts” and not send out a signal of its own. Then, on the 26th it will. And, so it will on the 27th, 28th, 29th etc. The threshold for that neuron was 26 jolts.

My thinking about chronic pain has been along the idea that nerves are initially reporting actual damage to the body, but then those nerves get pushed past their threshold and start sending pain signals at the drop of a hat.

As such, I was quite interested at a new article on pain in the June 2011 issue of Discover.

To A. Vania Apkarian, a neuroscientist at Northwestern University, the connection between the living memory and the never-ending pain suggest a glitch in the brain. Ordinary pain might turn chronic, he hypothesizes, when inflammation caused by conditions like arthritis or nerve damage provokes an abnormal rush of signals from nociceptors [neurons responsible for your sense of touch/pain etc.]. When these aberrant signals reach the pain network in the brain, Apkarian argues, they overwhelm it. The brain doesn’t get the chance to forget the pain. Instead it learns to feel it continuously. Eventually the neural connections become so strong that we no longer need the original stimuli anymore.

If you’re not following this, this guy is pretty much offering the same theory I have surmised, but with more detail. Clearly I should be upset that he’s stealing my ideas, but I’m more interested in helping people and am happy to see progress being made.

And progress is being made. Another scientist realized that the neural learning of chronic pain is accelerated when levels of an enzyme (I have no idea what the fuck and enzyme is — I think it causes certain chemical reactions) called AC1 is present in high levels. The scientist came up with a compound that blocks AC1 and it was shown that, in rats, this eliminates chronic pain. In essence, the rats forgot the pain that they’d learned. (Interestingly, the rest of their memory seemed unaffected.)

The gist of all this is: chronic pain is “learned” and methods that block this learning process can alleviate the pain.