Can we ‘forget’ chronic pain?
by Tim Hornyak, BA’95
If you’ve ever suffered from a recurring bad back, or any other type of chronic pain, you may involuntarily flinch when bending over or doing other movements. Will the agony return? Sometimes the pain lingers long after an injury.
It’s a stressful and even debilitating situation that neuroscientists such as Terence Coderre, MSc’83, PhD’85, are trying to remedy.
Coderre, an associate professor of anesthesia, has shed new light on how our nervous system records pain in a kind of chemical memory system. More important, Coderre and his colleagues are working on a way to erase those memories.
In a rat-based study described in the journal Molecular Pain, the researchers found that levels of the protein kinase PKMzeta increase in the central nervous system after exposure to pain, and create hypersensitivity to painful stimuli.
“This amplification can prolong pain inputs leading to persistent pain, or intensify responses to future inputs, resulting in pain hypersensitivity — for example, when touch feels like pain,” says Coderre.
When the team blocked the action of PKMzeta at the level of neurons, it reversed the hypersensitivity, proving that PKMzeta is essential in the process. “Our results also suggest that it is possible to erase pain memory traces in spinal cord neurons, and by doing so reverse pain hypersensitivity.”
Coderre says more research is needed, but the early results point to possible treatment of chronic pain, which affects some 20 per cent of Canadians.