New way to feel the detection of pain

Pain causes suffering and entails high costs for society. Almost all people in five suffer from persistent pain and it is absolutely necessary to find new painkillers. But sensitivity to pain is also necessary for survival and has a protective function. This leads to reflex reactions that prevent tissue damage, such as when you remove your hand when you feel a stick on a sharp object or burn.

Now scientists have at Karolinska Institutet has discovered a new sensory organ in the skin that detects a dangerous direction of the environment. It consists of glial cells that have many long projections that together form a tissue-like organ under the skin. This organ is susceptible to painful mechanical damage such as sticks and strokes.

The study describes what the new pain-sensitive organ looks like, how it is organized with pain-sensitive nerves in the skin and how its activation leads to electrical impulses in the nervous system that lead to reflex reactions and to a painful experience. The cells that make up the organ are very sensitive to the mechanical direction, which explains how they can detect sticks and strokes. In the experiments, the researchers also stopped the organ and found that the ability to detect mechanical pain decreased.

– Our study shows that sensitivity to pain occurs not only in the nerve fibers of the skin, but also from the cells of this newly discovered pain-sensitive organ. Discovery alters the perception of the underlying cellular mechanisms of body sensation and can impact the understanding of chronic pain, she says Patrik Ernfors, Professor in the Department of Medical Biochemistry and Biophysics of Karolinska Institutet and Senior Director of the Study.