According to some research from Northwestern University in Chicago, central nervous cell shrink when the organism has strong and chronic pain.
It is interesting, however, that if the pain is controlled the brain cells may be saved. Psychologists from Stanford University performed experiments dealing with the psychological control of pain. Eight patients with severe chronic pain were educated about the physiology of pain. They studied the parts of the brain responsible for pain using scans and models. After that the patients were trained to change the blood flow in these parts of the brain using imagery techniques. Instead of feel pain as something terrible, the patients were trained to think about something good. The experiment was successful for all eight patients. They have been able to decrease their perceived pain by at least half and feel that they are not so helpless.
To check if this was not a placebo effect, the patients divided into groups. One group was shown parts of brain not related to pain, the second group was not shown anything, and the third group was shown the brain of other people. The result: the more clear the picture that the person had, the more successful the imagery technique was. The lesson here is that e could decrease pain for so many people, if only they could have patience and persistence.