Chronic pain research
Project overview
At Queen’s University Belfast, Dr Ikhlas El Karim, Dr Fionnuala Lundy and PhD student Hayley McMillan are using extracted human teeth to discover uniquely human pain pathways and help save people – and animals – from chronic pain.
What’s the problem?
Did you know almost half of all UK adults may be living with chronic pain?
Current advice from the NHS is to use a combination of physical exercise and painkillers, along with cognitive behavioural therapy to help cope with quality of life. It’s clear that we need a better way to treat chronic pain for the 28 million adults who are suffering every day.
Sadly, traditional pain research inflicts considerable pain and suffering on animals. In some experiments, balloons are inserted into rats’ colons and then inflated to see how much pain the swelling of their abdomen causes them. In other experiments, once the animals have suffered through unnecessary surgery or being injected with chemicals, they undergo further tests – such as being forced to stand on a hot plate – to see how much pain they can withstand after their initial injuries.
You’re bound to agree that’s not the best way to do science. Experiments on animals’ nervous systems may not even translate to humans, placing a huge question mark over the validity – as well as the ethics – of this research.
How you are helping
Thanks to generous donations from people like you, we are funding a three-year project that’s being carried out by Dr Ikhlas El Karim, Dr Fionnuala Lundy and their brilliant PhD student, Hayley McMillan, at the dentistry school at Queen’s University Belfast. They’re working to replace the use of animals in chronic pain research by using human dental pulp instead of cruel experiments.

Dr Ikhlas El Karim, Hayley McMillan and Dr Fionnuala Lundy.
Ikhlas, Fionnuala and Hayley told us that sadly, animals are used by some researchers as a surrogate for human nerves because there are ethical issues associated with collecting human nerve tissue. However, they have developed an exciting new model based on nerve cells that can be grown directly from dental pulp tissue.
Dental pulp is a rich source of stem cells from which several cell types, including nerve cells, can be grown. The big plus is that it’s readily available from human tooth extraction – and only a very small number of teeth are needed to provide the tissue required.
What’s the impact of the research?
Now in the third year of their novel research project, the team is working to understand the molecular mechanisms that trigger chronic pain signals in nerves. They are isolating and investigating special receptor channels in human nerve cells to see how they are disrupted. Crucially, this receptor is totally different across species, so the receptor in this research is unique to humans.
By using human teeth instead of animals, they are the first researchers to produce human specific pain receptors from these nerve cells. Their findings will help the team – as well as other researchers – to understand more about the unique pain pathways in humans without forcing animals to suffer.