A sensory organ has been discovered in the skin that is able to detect painful mechanical damage such as pricks and impacts. The organ is composed of glia cells with multiple long protrusions that collectively make up a mesh-like organ within the skin.
The discovery by researchers at Karolinska Institutet in Sweden was published today in Science.
Their paper describes what the new pain-sensitive organ looks like, how it is organized together with pain-sensitive nerves in the skin, and how activation of the organ results in electrical impulses in the nervous system that result in reflex reactions and an experience of pain. The cells that make up the organ are highly sensitive to mechanical stimuli, which explain how they can participate in the detection of painful pinpricks and pressure. In experiments, the researchers also blocked the organ and saw a resultant decreased ability to feel mechanical pain.
"Our study shows that sensitivity to pain does not occur only in the skin's nerve fibres, but also in this recently-discovered pain-sensitive organ. The discovery changes our understanding of the cellular mechanisms of physical sensation and it may be of significance in the understanding of chronic pain," says Patrik Ernfors, chief investigator for the study.