London, Feb. 21: Only a tiny genetic difference can separate a macho man from a wimp, says a study published today.
A variation in a single gene may explain why some people can withstand pain — or other physical or emotional stress — better than others, a team from the University of Michigan and the National Institutes of Health reports.
In the journal Science, the team describes how a small variation in the gene encoding an enzyme — catechol-O-methyl transferase, or COMT — made a significant difference in the pain tolerance, and pain-rel- ated emotions and feelings, of volunteers.
Genetics may not make all the difference between wimps and Marines, but the finding adds to evidence of variations in individuals’ response to pain being mainly due to biological factors affecting the brain.
In the study, the pain came from a carefully controlled salt-water injection into the jaw muscles of the volunteers.
By combining genetic testing with molecular brain imaging techniques the researchers could see how well participants’ brains controlled pain, and how they felt as a result, depending on their COMT.
The research could help explain how perceptions of pain affect chronic conditions and depressive illness. “Examining and detailing the biochemistry of these processes can then lead to more effective treatments,” said Dr Zubieta.