title: painless, a Drosophila gene essential for nociception.
abstract: We describe a paradigm for nociception in Drosophila. In response to the touch of a probe heated above 38 degrees C, Drosophila larvae produce a stereotypical rolling behavior, unlike the response to an unheated probe. In a genetic screen for mutants defective in this noxious heat response, we identified the painless gene. Recordings from wild-type larval nerves identified neurons that initiated strong spiking above 38 degrees C, and this activity was absent in the painless mutant. The painless mRNA encodes a protein of the transient receptor potential ion channel family. Painless is required for both thermal and mechanical nociception, but not for sensing light touch. painless is expressed in peripheral neurons that extend multiple branched dendrites beneath the larval epidermis, similar to vertebrate pain receptors. An antibody to Painless binds to localized dendritic structures that we hypothesize are involved in nociceptive signaling.
authors.affiliation: Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA. tracey@caltech.edu
authors.forename: W Daniel
authors.initials: WD
authors.lastname: Tracey
authors.forename: Rachel I
authors.initials: RI
authors.lastname: Wilson
authors.forename: Gilles
authors.initials: G
authors.lastname: Laurent
authors.forename: Seymour
authors.initials: S
authors.lastname: Benzer
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D015220:Calcium Channels / Q000235:genetics / Q000302:isolation & purification*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000302:isolation & purification*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000235:genetics / Q000302:isolation & purification*; D007473:Ion Channels / Q000235:genetics / Q000302:isolation & purification*; D007814:Larva / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009420:Nervous System / Q000166:cytology / Q000378:metabolism; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism; D009619:Nociceptors / Q000166:cytology / Q000378:metabolism*; D010146:Pain / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010812:Physical Stimulation; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D050051:Transient Receptor Potential Channels
chemical_list: D015220:Calcium Channels; D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; D007473:Ion Channels; D050051:Transient Receptor Potential Channels; C474592:pain protein, Drosophila; C063169:trp protein, Drosophila