About 17 percent of the Canadian population above 15 years of age has reported experiencing some form of chronic pain. Though chronic pain can be a result of an acute injury, in some instances the perception of pain continues even after an injury has healed. This has caused scientists to wonder: what causes the body to continue perceiving pain?
An artist’s rendition of a strand of DNA.
A team of researchers including Senior Fellow Moshe Szyf (McGill) published a paper in PLOS One that may have an answer. The paper is the first to link chronic pain to epigenetic changes in the brain – a process that might explain why the body retains a “memory” of being injured. Epigenetic changes – chemical modifications to DNA that affect gene expression – can have long-term effects on how our genes behave and on our overall well-being.
The research team discovered a mechanism that embeds the memory of an injury directly into our brain’s DNA through a chemical tagging process called DNA methylation. Methylation is the addition of simple compounds made out of carbon and hydrogen to DNA, which leaves a mark on genes that serves as the “memory” of an experience. This work is linked to the team’s previous study which showed that experiences themselves – rather than something tangible like chemicals– can also result in DNA methylation resulting in epigenetic changes.
“We know that epigenetic marks are potentially reversible,” says Dr. Szyf. “This study therefore suggests a new approach to curing chronic pain by epigenetic interventions by using either drugs that reverse epigenetic markings, or through behavioural interventions that could do the same.”
This study was funded by the Canadian Institutes of Health Research.