WASHINGTON -- Is it nature or nurture? Why does one medication give relief for one person but not for another? Is it the same for men and women? The "it" is pain, and research is providing an improving handle on how to deal with it. With 62 studies behind him, Jeffrey Mogil of the University of Illinois is narrowing the search for specific genes responsible for a person's response to pain. In a speech Saturday at the American Association for the Advancement of Science annual meeting in Washington, D.C., he said he had established two principles regarding the link between genes and pain response:
Mogil, a professor of psychology and neuroscience, studies the genetic variability of pain, using inbred mice and rats doing "tail-flick tests" in hot water, for example.
Mogil has found that 50 percent of animals tested both feel and respond to pain, while 50 percent don't feel it or better tolerate it. He has found huge differences between strains -- some barely tolerate it, and some seem not to mind at all. Part of the differences, he said, reflect such factors as experience, age, stress and diet; part are from genetic biological inputs such as sex, hormones and stress; and part reflect genotype (inherited genes). "Our technique tells us about where the pain gene is located, but it doesn't tell us what gene it is or exactly where it is located," Mogil said. "If the genome is the United States, I know that for a particular gene trait there is a gene living in Iowa that is responsible. But I don't know what city, what neighborhood or what house. We can do more focused searches. Mostly, we are consulting Iowa's phone book to see what genes already known to live in Iowa look interesting."
The big phone book -- the Mouse Genome Project (like the human effort, an attempt to sequence the entire genome of this species) -- may speed the search, he said. Based on research to date and on the promise of findings to come, Mogil said there are three implications for the understanding and treatment of pain.
Mogil in 1998 received the John C. Liebeskind Early Career Scholar Award from the American Pain Society and the Neal E. Miller New Investigator Award from the Academy of Behavioral Medicine Research. Reporting in the Journal of Neuroscience in October 1997, Mogil identified a chromosomal location linked to pain response specific to female mice.