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New discoveries hold promise of custom-made pain remedies

WASHINGTON: "New discoveries about how variations in genes and in the brain control how people feel pain could soon lead to treatments for chronic pain that are tailored to individual patients," researchers said, according to the 'Chicago Tribune'.

The report said, quoting Allan Busbaum, a neuroscientist at the University of California at San Francisco, that one the most promising developments in recent years was the discovery of chemical receptors in the brain that respond only to specific types of pain, such as that from hot peppers. Such discoveries had spurred tremendous interest among molecular biologists who never studied pain before, but now see a chance to break new ground, he said. "The pain system is rich in unique molecules," he told the annual meeting of the American Association for the Advancement of Science.

The newspaper report said, "the short-lived pain most people feel when they stub a toe or touch a hot surface actually is good because it helps them avoid danger. But that beneficial response goes terribly wrong in conditions such as arthritis, cancer or phantom pain from a lost limb, when otherwise normal activities may cause intense pain."

Catherine Bushnell, a professor of psychology at McGill University in Montreal, told the conference that the brain circuits that governed pain were the same for the brief and chronic pain. Using brian scans taken of patients as they touched something hot, Bushnell found that pain arises in the brain area responsible for emotion, as well as in the region that processes normal touch sensations. In some cases, Bushnell said, people may be able to change how their brain interprets sensations that normally would be painful. Bushnell found that experimental subjects who were distracted by listening to a tone while touching a hot surface had less activity in the parts of their brain that process pain. "It suggests that a psychological phenomenon creates change in this brain circuit the same as if you gave the person morphine," Bushnell said.

Jeffrey Mogil, a professor of psychology and neuroscience at the University of Illinois at Urbana-Champaign, said recent studies on mice had indicated that some individuals were naturally more sensitive to pain than others.

About half the difference came from genes, which would help explain why women generally were more sensitive to pain than men were "if we understood these individual differences, our therapies might work better," Mogil said. "We're trying to dissect the genetic basis of pain."

He stressed that it would take many years to translate such information into gene therapy for pain, but there may be simple genetic tests that could show how susceptible people were to severe pain. Such tests may one day become standard procedure for patients about to go into surgery. "That could tell us how much pain they'll be in when they wake up," Mogil said. Doctors could use that knowledge to adjust the amount of morphine or other pain relievers a patient was given. APP