Editors' ChoiceNeuroscience

A Separate System for Itch Processing

Science Signaling  22 Sep 2009:
Vol. 2, Issue 89, pp. ec315
DOI: 10.1126/scisignal.289ec315

It has been a long-standing question whether itch is a subquality of pain involving the same neuronal elements or whether distinct, so-called labeled lines exist in the nervous system for both sensations. To address this question directly, Sun et al. destroyed neurons in the superficial spinal dorsal horn that express the gastrin-releasing peptide receptor. This receptor is known to be involved in mediating itch but not pain sensations. In various animal models, ablation of gastrin-releasing peptide receptor–expressing spinal dorsal horn neurons reduced itch without changing pain perception. Thus, itch and pain indeed appear to be mediated by distinct labeled lines in the central nervous system.

Y.-G. Sun, Z.-Q. Zhao, X.-L. Meng, J. Yin, X.-Y. Liu, Z.-F. Chen, Cellular basis of itch sensation. Science 325, 1531–1534 (2009). [Abstract] [Full Text]