Body's own marijuana keeps pain at bay

Researchers in Galway have discovered how the brain manages to switch off pain during times of high octane stress or extreme fear. It produces its own marijuana-like drug that keeps pain at a distance until the stress has passed.

Marathon runners experience it, and so too do soldiers on a battlefield. If highly stressed the body can switch off the normal pain response caused by injury and park it until the stress goes.

Dr David Finn and his research team at NUI Galway have discovered an essential component of this pain-suppression system. Dr Finn is leader of the Galway Neuroscience Centre and co-director of the Centre for Pain Research there and has published high profile research in the area of pain control.

Being able to ignore pain is an important evolutionary survival skill, allowing our early ancestors to escape from danger despite injury, Dr Finn explained. This latest research, funded by Science Foundation Ireland and published in the current issue of the journal Pain, describes the involvement of an area of the brain known as the amygdala.

“The amygdala is very important in our response to fear and stress,” Dr Finn said. His team carried out a series of experiments that showed that these emotions triggered the release of a kind of natural marijuana in the body.

“We found that the body’s own marijuana-like chemicals were released in the amygdala, and when released they were very important in the suppression of pain in times of stress,” he said.

These substances in turn interacted with other important neurotransmitters in the brain as part of the pain shut-down process. The effect can be very powerful, as evidenced in the case of legendary footballer Bert Trautmann, Dr Finn said.

Trautmann played for Manchester City in the 1956 FA Cup Final when with 17 minutes remaining he made a diving save and injured his neck. He continued playing, making crucial saves that allowed City to win 3-1.

Medical checks that followed revealed he had broken his neck but he had managed to play through to the finish, unaware of the damage that had been done.