Role of Dopamine in Pain

In cases of acute pain suffered after an injury, pain signals are sent from the site of injury, to the spinal cord, which, in turn, relays them to brain cells which then spread them throughout the brain. In chronic pain conditions, however, neurons continue sending pain signals to the brain, even when there has not been any injury. It is estimated by the Institute of Medicine that more than 100 million individuals in the US suffer from chronic pain, which results in around $600 billion being spent per year on lost productivity and medical care.

This year, researchers from the University of Texas published a study in the Journal of Neuroscience showing that dopamine may play a key role in maintaining chronic pain. The researchers traced the pain signalling pathway between the brain and spinal cord in an animal model and found that removing dopamine-containing cells reduced chronic pain.

The study demonstrated that a group of cells containing dopamine, referred to as A11, have no effect on acute pain, but do seem to have a significant effect on chronic pain. The researchers believe the study increases the understanding of the factors that contribute to pain, which could eventually lead to improved treatments. Lead author of the paper, Ted Price, says that the finding could open up new opportunities for targeting medicines that can reverse chronic pain.

In the future, the team would like to investigate the interaction between stress and A11 and to find out more about the molecular mechanisms that promote dopamine and chronic pain.