Cellular basis of itch sensation.
Itch and pain are two distinct sensations. Although our previous study suggested that gastrin-releasing peptide receptor (GRPR) is an itch-specific gene in the spinal cord, a long-standing question of whether there are separate neuronal pathways for itch and pain remains unsettled. We selectively ablated lamina I neurons expressing GRPR in the spinal cord of mice. These mice showed profound scratching deficits in response to all of the itching (pruritogenic) stimuli tested, irrespective of their histamine dependence. In contrast, pain behaviors were unaffected. Our data also suggest that GRPR+ neurons are different from the spinothalamic tract neurons that have been the focus of the debate. Together, the present study suggests that GRPR+ neurons constitute a long-sought labeled line for itch sensation in the spinal cord.
Sun
Yan-Gang
YG
Departments of Anesthesiology, Psychiatry, and Developmental Biology, Washington University School of Medicine Pain Center, St. Louis, MO 63110, USA.
Zhao
Zhong-Qiu
ZQ
Meng
Xiu-Li
XL
Yin
Jun
J
Liu
Xian-Yu
XY
Chen
Zhou-Feng
ZF
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal; D001839:Bombesin / Q000494:pharmacology; D002908:Chronic Disease; D006632:Histamine; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D010146:Pain / Q000503:physiopathology; D011537:Pruritus / Q000503:physiopathology*; D018004:Receptors, Bombesin / Q000235:genetics / Q000378:metabolism*; D054789:Ribosome Inactivating Proteins, Type 1 / Q000494:pharmacology; D000076985:Saporins; D012677:Sensation / Q000502:physiology; D013116:Spinal Cord / Q000166:cytology*; D013133:Spinothalamic Tracts / Q000166:cytology / Q000502:physiology
D018004:Receptors, Bombesin; D054789:Ribosome Inactivating Proteins, Type 1; D006632:Histamine; D000076985:Saporins; D001839:Bombesin