title: The coding of cutaneous temperature in the spinal cord.
abstract: The spinal cord is the initial stage that integrates temperature information from peripheral inputs. Here we used molecular genetics and in vivo calcium imaging to investigate the coding of cutaneous temperature in the spinal cord in mice. We found that heating or cooling the skin evoked robust calcium responses in spinal neurons, and their activation threshold temperatures distributed smoothly over the entire range of stimulation temperatures. Once activated, heat-responding neurons encoded the absolute skin temperature without adaptation and received major inputs from transient receptor potential (TRP) channel V1 (TRPV1)-positive dorsal root ganglion (DRG) neurons. By contrast, cold-responding neurons rapidly adapted to ambient temperature and selectively encoded temperature changes. These neurons received TRP channel M8 (TRPM8)-positive DRG inputs as well as novel TRPV1(+) DRG inputs that were selectively activated by intense cooling. Our results provide a comprehensive examination of the temperature representation in the spinal cord and reveal fundamental differences in the coding of heat and cold.
authors.affiliation: Department of Biology, Stanford University, Stanford, California, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Ran
authors.affiliation: National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hoon
authors.affiliation: Department of Biology, Stanford University, Stanford, California, USA.
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003080:Cold Temperature / Q000009:adverse effects; D005727:Ganglia, Spinal / Q000378:metabolism*; D006358:Hot Temperature / Q000009:adverse effects; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000378:metabolism*; D012881:Skin Temperature; D013116:Spinal Cord / Q000378:metabolism*; D050053:TRPM Cation Channels / Q000378:metabolism
chemical_list: D050053:TRPM Cation Channels; D002118:Calcium