Researchers from the University of Texas (UT) at Dallas and others traced the path of pain signals between the brain and spinal cord in mice and found removing a group of dopamine-containing cells selectively reduced chronic pain.
Ted Price, associate professor in behavioral and brain sciences at UT Dallas, says the study reveals a new role for dopamine in helping maintain chronic pain states, and suggests:
“This may open up new opportunities to target medicines that could reverse chronic pain.”
In people with chronic pain, their nerve cells continue to send pain signals to the brain – even in the absence of injury – but the causes of this are not known.
The brain has several pain centers, and evidence suggests chronic pain alters how they are activated.
The new study shows that a group of dopamine-containing cells called A11do not affect acute pain, but they appear to have a profound effect on chronic pain.
This demonstrates the biological difference between acute and chronic pain. Chronic pain is not just acute pain that continues, but a separate phenomenon all together.
“We used a toxin that affected A11 neurons, and that’s when we found that acute pain signals were still normal, but chronic pain was absent.”
The researchers conclude their study increases our understanding of the causes of chronic pain and the factors that contribute to it, which should eventually lead to more effective treatments
“In future studies, we would like to gain a better understanding of how stress interacts with A11. And we’d like to know more about the interaction between molecular mechanisms that promote chronic pain and dopamine.”
My next post will show how chronic pain affects the “dopamine response”, which is what causes the “high” and leads to addiction in some people.