Y: Hey Don, a team of Swedish biomedical researchers have just discovered a new organ in the bodies of mice, and they expect that humans have it too.
D: Come on, Yaël, how could they have missed a whole organ!?
Y: They missed it until now because it’s not a complicated organ like a heart or a liver. It’s a fairly simple sensory organ in the skin that appears to play a critical role in perceiving pain. The sensory organ causes pain when the skin is damaged by sharp things, like a stabbing needle, pressure, or burning.
D: But I thought bare nerve endings in the skin detected these kinds of painful stimuli.
Y: That’s what scientists used to think, until they found the new organ. It includes nerve endings assisted by a network of cells called Schwann cells. Neuroscientists already knew that Schwann cells protect and support nerve cells in other circumstances.
D: So, how do the Schwann cells help nerve cells detect painful stimuli?
Y: They form a mesh-like network at the base of the skin, which is intertwined with fibers of collagen. This allows them to detect anything that would damage the skin by stretching or breaking.
D: But how could the scientists tell that this organ caused pain in mice?
Y: They used genetic engineering to make these particular Schwann cells sensitive to light. When they shined a bright light on the mouse’s paw, the mouse displayed signs of pain, like jerking the paw away and licking it.D: If the scientists can confirm that the organ is found in humans, too, this new knowledge might be really useful for things like controlling chronic pain.