By Imogen Howse via SWNS
People who carry three gene variants inherited from Neanderthals are more sensitive to pain, a new study has discovered.
Researchers analyzed a group of 1,963 people from Colombia and measured their pain thresholds in response to a range of stimuli.
They found that those who carried the sensory neuron gene SCN9A and had one of the three so-called Neanderthal variants – known as M932L, V991L, AND D1908G – were more sensitive to pain from skin pricking after exposure to mustard oil.
Those who had all three of the variants had even higher pain sensitivity.
However, none of the variants were associated with lower pain thresholds when it came to heat or pressure.
The findings, published in Communications Biology, are the latest to demonstrate how interbreeding with Neanderthals has influenced the genetics of modern-day humans.
Scientists have established that the SCN9A gene is responsible for encoding a sodium channel that detects signals from damaged tissue.
It then expresses this in high levels through sensory neurons.
Author Dr. Pierre Faux suggests that the Neanderthal variants may further sensitize the sensory neurons by altering the threshold at which a nerve impulse is generated, thereby changing responses to pain.
Analysis of the genomic region suggests that the three Neanderthal variants were more common in countries with higher proportions of Native American ancestry, such as Peru.
This could be a result of random chance, or possibly linked to bottlenecks that occurred during the initial occupation of the Americas.
Co-author Dr. Kaustubh Adhikari said further research is needed to determine whether these greater levels of pain sensitivity were advantageous to human evolution.
He explained: “Pain sensitivity is an important survival trait that enables us to avoid things that could cause us serious harm.
“Our findings suggest that Neanderthals may have been more sensitive to certain types of pain but further research is needed for us to understand why that is the case, and whether these specific genetic variants were evolutionarily advantageous.”
Dr. Faux added: “We have shown how variation in our genetic code can alter how we perceive pain, including genes that modern humans acquired from the Neanderthals.
“But genes are just one of many factors, including environment, past experience, and psychological factors, which influence pain.”
The new study, led by researchers at UCL, Aix-Marseille University, University of Toulouse, Open University, Fudan University, and Oxford University, follows previous research – also by Dr. Adhikari – which shows that humans inherited genetic material from Neanderthals which affects the shape of our noses.
He said: “In the last 15 years, since the Neanderthal genome was first sequenced, we have been learning more and more about what we have inherited from them as a result of interbreeding tens of thousands of years ago.”
