Photo credit: David Mark/Pixabay.com
Date: 31 July 2020
Institution: Karolinska Institutet & Max Planck Institute
Study published in: Current Biology
Digest: The human perception of pain may have been influenced by events taking place 50,000-70,000 years ago when our ancestors met the Neanderthals. A Neanderthal gene confers increased sensitivity to pain according to new research. These findings could lead to more tailored treatments.
“It is difficult to say whether Neanderthals felt more pain than we do today since pain is also modulated in the spinal cord and in the brain. But this work shows that their threshold for initiating pain signals was lower than in most people today,” says Hugo Zeberg, researcher at Karolinska Institutet and the principal author of the study.
Pain is transmitted through specialised neurons. These neurons have a special ion channel which plays a key part in starting the electrical pain impulse sent to the brain.
Selection from British biobank
In the article, “A Neanderthal sodium channel increase pain sensitivity in present-day humans”, published in the journal Current Biology, Hugo Zeberg, Svante Pääbo, and their co-authors show that some of us have inherited the pain-initiating ion channel from the Neanderthals.
Interestingly, people with the Neanderthal ion channel perceive more pain than others. The study is based on a sample of 362,944 individuals from a British biobank.
For around 500,000 years, the Neanderthals and their Asian relatives, the Denisovans, evolved largely separately from the ancestors of modern-day humans. During this period, genetic changes occurred within each of the groups.
Some 50,000 – 70,000 years ago, Neanderthals, Denisovans, and modern-day human ancestors met and interbred, mixing their genetic material.
These interbreeding events occurred relatively late in our evolutionary history and several gene variants passed down from the Neanderthals can still be found in modern humans. The access to Neanderthal genomes makes it possible to identify these variants, examine their physiological effects and assess which consequences they have for people living today.
The researchers have shown that some people have inherited a special Neanderthal variant of an ion channel that transmits pain information from the nerves to the brain.
“Substituting single amino acids does not affect the function of the ion channel. However, the complete Neanderthal variant, which involves three amino acid changes, can lead to increased pain sensitivity in modern-day humans. At the molecular level, the Neanderthal ion channel is more likely to be activated, which could explain why those who have inherited it have a lower pain threshold,” says Kristoffer Sahlholm, co-author and active at Karolinska Institutet and Umeå University.
The study found no difference between genders when it comes to perceived pain. However, in general, people report more pain with increased age.
“A better understanding of why the pain threshold is so individual could lead to tailored treatments,” says Hugo Zeberg.
The research was funded by the NOMIS Foundation and Max Planck Society. The authors have no competing interests.
Source: Karolinska Institutet
Interested in original study: read here