An artist’s rendition of nerve cells monitoring the surface of the skin where they may encounter pain stimulants like capsaicin, found in hot peppers, and itch stimulants like histamine. (Credit: Copyright Tim Phelps, Department of Art as Applied to Medicine, Johns Hopkins University, 2012
Jan. 2, 2013 — Johns Hopkins researchers have uncovered strong evidence that mice have a specific set of nerve cells that signal itch but not pain, a finding that may settle a decades-long debate about these sensations, and, if confirmed in humans, help in developing treatments for chronic itch, including itch caused by life-saving medications.At the heart of their discovery is a type of sensory nerve cell whose endings receive information from the skin and relay it to other nerves in the spinal cord, which then coordinates a response to the stimulus. Published online Dec. 23 in Nature Neuroscience, a report on the research suggests that even when the itch-specific nerve cells receive stimuli that are normally pain-inducing, the message they send isn’t “That hurts!” but rather “That itches!”
More: http://www.sciencedaily.com/releases...0102104548.htm