Most people reflexively pull their hand away when, for example, they stick to a sharp object or burn on a hot stove. Feeling pain when the body comes into contact with objects that can cause tissue damage is the body's way of protecting itself.

Now researchers at the Karolinska Institute, KI, have discovered a new sensory organ in the skin that senses these pains and other dangerous directions from the environment. The discovery is published in the scientific journal Science.

"In the past, it has been thought that pain has started from nerve fibers in the skin, but we have discovered that there is also another cell type that knows the environment and responds to pain," says Patrik Ernfors, professor at the Department of Medical Biochemistry and Biophysics at the Karolinska Institute, and the principal of the study.

"Finally proved it"

The sensory organ consists of cells that together form a tissue-like organ under the skin and are sensitive to painful mechanical action. When the sticks and strokes activate the organ, it leads to electrical impulses in the nervous system that lead to reflex reactions and the person feels pain.

- They lie like long protrusions, a tissue, in the skin. I think both their appearance and how it works is exciting, says Patrik Ernfors.

How does it feel now?

- We have been researching this for five years, so we have known this cell type for a long time, but now we have finally proved it. So for us, it is not an end but rather a beginning to find out more, says Patrik Ernfors.

"Can make sense"

The KI researchers also conducted experiments in which they shut down the organ and saw that the possibility of sensing mechanical pain decreased. Patrik Ernfors hopes that the discovery will have a bearing on the understanding of chronic pain.

- It opens up a lot of exciting questions if we hope to be able to participate and answer. If we understand how pain arises, we may also understand what causes chronic pain. A next step is then to be able to produce medicines for those who suffer from constant pain, says Patrik Ernfors.