We might have the answer to painlessness: scientists have genetically modified mice so that the latter cannot feel pain. The research is published in Nature Communications.
While pain is a necessary ingredient for life on Earth, humans still attempt to get away from it. Some people, though, are actually unable to feel it: those born with a rare genetic mutation cannot experience pain. Scientists have tried to reproduce this effect into drugs to heal chronic pain patients, but have remained unsuccessful. Until now. In a new study, scientists from University College London (UCL) have brought about the same mutation in mice, and probed further to find answers.
The UCL researchers modified mice to incorporate the rare human mutation involving a sodium channel (called Nav1.7). The latter’s role entails signalling in pain pathways, and those born without Nav1.7 do not feel pain.
When the mice were examined, it was found that those lacking Nav1.7 would also have natural opioid peptides above the normal range.
When the scientists attempted to test whether opioids were relevant to painlessness, by giving an opioid blocker called naloxone to the mice without Nav1.7, they found that the latter were then able to feel pain.
Naloxone was then given to a 39-year-old woman with the mutation: she ultimately experienced pain for the first time ever.
Thus has it been confirmed that Nav1.7 is indeed an important factor in human pain, as points out one of the UCL authors, Professor John Wood.
The team, therefore, filed a patent to merge low doses of opioids with Nav1.7 blockers so as to bring about painlessness.
Local anaesthetics normally use broad-spectrum sodium channel blockers which do not cater for sustained pain management. As for opioid painkillers like morphine, they are linked with addiction if used for a long time period. Fortunately, this would not be an issue with opioids: people with the rate mutation produce low amounts thereof and live without facing unpleasant side effects.
The new approach will be tested in humans by 2017 as a further step in trying to alleviate the suffering of chronic pain patients.