Scientists discover how to 'turn off' pain: Threshold can be raised by altering chemistry in the brain
Patients can be made more resistant to pain by altering the structure of their brains, scientists believe.
New research has raised the possibility of creating more effective treatments for people who suffer from chronic pain - which could be as simple as encouraging them to take more exercise.
Scientists discovered for the first time that people left in agony by arthritis develop more receptors in the brain that respond to opiate pain relief.
Having extra receptors makes the body more resistant to pain – both by using our bodies’ natural painkillers, endorphins, and through prescribed opiates such as morphine.
The researchers believe that if we can find out how the body increases the number of opiate receptors, we will be able to improve pain relief treatments.
Nearly half of the UK population are thought to have suffered from chronic long-term pain – lasting six months or more - and one in five consultations with GPs are for this complaint.
But some people seem to cope better with long-term severe pain, leading scientists to investigate which coping mechanisms were at work.
The University of Manchester team found that the more opiate receptors an individual has, the better able they are to resist pain.
To test the theory, the scientists warmed the skin of patients with a laser to measure how much pain they could withstand.
They then scanned their brains with a PET scanner to count the number of opiate receptors.
They found that arthritis patients who had suffered more recent severe pain had more opiate receptors.
Professor Anthony Jones, director of the Manchester Pain Consortium, said: ‘This is very exciting because it changes the way we think about chronic pain.
‘There is generally a rather negative and fatalistic view of chronic pain. This study shows that although the group as a whole are more physiologically vulnerable, the whole pain system is very flexible and that individuals can adaptively increase their resilience to pain.
‘It may be that some simple interventions can further enhance this natural process, and designing smart molecules or simple non-drug interventions to do a similar thing is potentially attractive.’
Researchers believe that increasing the amount of exercise we do could increase pain resistance (file photo)
Prof Jones said that as well as drug treatments, something as simple as taking exercise could also boost opiate receptors.
‘We know that exercise can activate the natural opiate system in the brain,’ he told the Daily Mail.
‘What we don’t know is how it regulates how many opiate receptors we have. Having more exercise might increase the number of opiate receptors.’
The notion of enhancing the natural opiates in the brain, such as endorphins, as a response to pain, seems to me to be infinitely preferable to long term medication with opiate drugs.
Fellow researcher Dr Christopher Brown, from Manchester University, said: ‘As far as we are aware, this is the first time that these changes have been associated with increased resilience to pain and shown to be adaptive.
‘Although the mechanisms of these adaptive changes are unknown, if we can understand how we can enhance them, we may find ways of naturally increasing resilience to pain without the side effects associated with many pain killing drugs.’
Val Derbyshire, a patient who suffers chronic pain from osteoarthritis, said she was ‘extremely interested’ in the research.
‘I feel I have developed coping mechanisms to deal with my pain over the years, yet still have to take opioid medication to relieve my symptoms,’ she added.
‘The fact that this medication has to be increased from time to time concerns me greatly, due to the addictive nature of these drugs.
‘The notion of enhancing the natural opiates in the brain, such as endorphins, as a response to pain, seems to me to be infinitely preferable to long term medication with opiate drugs.
‘Anything that can reduce reliance on strong medication must be worth pursuing.’
Opiate receptors were first discovered in the brain in 1973. Since then they have been found to have several different sub-types with different roles.