Pain is a significant medical concern and represents a major unmet clinical need. The ability to perceive and react to tissue-damaging stimuli is essential in order to maintain bodily integrity in the face of environmental danger. To prevent damage the systems that detect noxious stimuli are therefore under strict evolutionary pressure. We developed a high-throughput behavioral method to identify genes contributing to thermal nociception in the fruit fly and have reported a large-scale screen that identified the Ca2+ channel straightjacket (stj) as a conserved regulator of thermal nociception. Here we present the minimal anatomical and neuronal requirements for Drosophila to avoid noxious heat in our novel behavioral paradigm. Bioinformatics analysis of our whole genome data set revealed 23 genes implicated in Ca2+ signaling that are required for noxious heat avoidance. One of these genes, the conserved thermoreceptor TrpA1, was confirmed as a bona fide “pain” gene in both adult and larval fly nociception paradigms. The nociceptive function of TrpA1 required expression within the Drosophila nervous system, specifically within nociceptive multi-dendritic (MD) sensory neurons. Therefore, our analysis identifies the channel TRPA1 as a conserved regulator of nociception.
References
[1]
Helme RD, Gibson SJ (2001) The epidemiology of pain in elderly people. Clin Geriatr Med 17: 417–431, v.
[2]
Woolf CJ (2010) Overcoming obstacles to developing new analgesics. Nat Med 16: 1241–1247.
[3]
Neely GG, Hess A, Costigan M, Keene AC, Goulas S, et al. (2010) A genome-wide Drosophila screen for heat nociception identifies alpha2delta3 as an evolutionarily conserved pain gene. Cell 143: 628–638.
[4]
Cosens DJ, Manning A (1969) Abnormal electroretinogram from a Drosophila mutant. Nature 224: 285–287.
[5]
Montell C, Rubin GM (1989) Molecular characterization of the Drosophila trp locus: a putative integral membrane protein required for phototransduction. Neuron 2: 1313–1323.
[6]
Wang H, Woolf CJ (2005) Pain TRPs. Neuron 46: 9–12.
[7]
Tracey WD Jr, Wilson RI, Laurent G, Benzer S (2003) painless, a Drosophila gene essential for nociception. Cell 113: 261–273.
[8]
Kang K, Pulver SR, Panzano VC, Chang EC, Griffith LC, et al. (2010) Analysis of Drosophila TRPA1 reveals an ancient origin for human chemical nociception. Nature 464: 597–600.
[9]
Glauser DA, Chen WC, Agin R, Macinnis BL, Hellman AB, et al. (2011) Heat Avoidance Is Regulated by Transient Receptor Potential (TRP) Channels and a Neuropeptide Signaling Pathway in Caenorhabditis elegans. Genetics 188: 91–103.
[10]
Hong ST, Bang S, Hyun S, Kang J, Jeong K, et al. (2008) cAMP signalling in mushroom bodies modulates temperature preference behaviour in Drosophila. Nature 454: 771–775.
[11]
Gioia A, Zars T (2009) Thermotolerance and place memory in adult Drosophila are independent of natural variation at the foraging locus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 195: 777–782.
[12]
Xu SY, Cang CL, Liu XF, Peng YQ, Ye YZ, et al. (2006) Thermal nociception in adult Drosophila: behavioral characterization and the role of the painless gene. Genes Brain Behav 5: 602–613.
[13]
Dubnau J, Grady L, Kitamoto T, Tully T (2001) Disruption of neurotransmission in Drosophila mushroom body blocks retrieval but not acquisition of memory. Nature 411: 476–480.
[14]
Suh GS, Wong AM, Hergarden AC, Wang JW, Simon AF, et al. (2004) A single population of olfactory sensory neurons mediates an innate avoidance behaviour in Drosophila. Nature 431: 854–859.
[15]
Wu Q, Zhao Z, Shen P (2005) Regulation of aversion to noxious food by Drosophila neuropeptide Y- and insulin-like systems. Nat Neurosci 8: 1350–1355.
[16]
Sayeed O, Benzer S (1996) Behavioral genetics of thermosensation and hygrosensation in Drosophila. Proc Natl Acad Sci U S A 93: 6079–6084.
[17]
Zars T (2001) Two thermosensors in Drosophila have different behavioral functions. J Comp Physiol A 187: 235–242.
[18]
Al-Anzi B, Tracey WD Jr, Benzer S (2006) Response of Drosophila to wasabi is mediated by painless, the fly homolog of mammalian TRPA1/ANKTM1. Curr Biol 16: 1034–1040.
[19]
Connolly JB, Roberts IJ, Armstrong JD, Kaiser K, Forte M, et al. (1996) Associative learning disrupted by impaired Gs signaling in Drosophila mushroom bodies. Science 274: 2104–2107.
[20]
Aso Y, Grubel K, Busch S, Friedrich AB, Siwanowicz I, et al. (2009) The mushroom body of adult Drosophila characterized by GAL4 drivers. J Neurogenet 23: 156–172.
[21]
Zars T, Fischer M, Schulz R, Heisenberg M (2000) Localization of a short-term memory in Drosophila. Science 288: 672–675.
[22]
Waddell S, Armstrong JD, Kitamoto T, Kaiser K, Quinn WG (2000) The amnesiac gene product is expressed in two neurons in the Drosophila brain that are critical for memory. Cell 103: 805–813.
[23]
Cheng HY, Pitcher GM, Laviolette SR, Whishaw IQ, Tong KI, et al. (2002) DREAM is a critical transcriptional repressor for pain modulation. Cell 108: 31–43.
[24]
Jung J, Shin JS, Lee SY, Hwang SW, Koo J, et al. (2004) Phosphorylation of vanilloid receptor 1 by Ca2+/calmodulin-dependent kinase II regulates its vanilloid binding. J Biol Chem 279: 7048–7054.
[25]
Hsueh YP (2006) The role of the MAGUK protein CASK in neural development and synaptic function. Curr Med Chem 13: 1915–1927.
[26]
del Camino D, Murphy S, Heiry M, Barrett LB, Earley TJ, et al. (2010) TRPA1 contributes to cold hypersensitivity. J Neurosci 30: 15165–15174.
[27]
Kwan KY, Allchorne AJ, Vollrath MA, Christensen AP, Zhang DS, et al. (2006) TRPA1 contributes to cold, mechanical, and chemical nociception but is not essential for hair-cell transduction. Neuron 50: 277–289.
[28]
Gracheva EO, Ingolia NT, Kelly YM, Cordero-Morales JF, Hollopeter G, et al. (2010) Molecular basis of infrared detection by snakes. Nature 464: 1006–1011.
[29]
Rosenzweig M, Brennan KM, Tayler TD, Phelps PO, Patapoutian A, et al. (2005) The Drosophila ortholog of vertebrate TRPA1 regulates thermotaxis. Genes Dev 19: 419–424.
[30]
Hamada FN, Rosenzweig M, Kang K, Pulver SR, Ghezzi A, et al. (2008) An internal thermal sensor controlling temperature preference in Drosophila. Nature 454: 217–220.
[31]
Lee Y, Lee Y, Lee J, Bang S, Hyun S, et al. (2005) Pyrexia is a new thermal transient receptor potential channel endowing tolerance to high temperatures in Drosophila melanogaster. Nat Genet 37: 305–310.
[32]
Kremeyer B, Lopera F, Cox JJ, Momin A, Rugiero F, et al. (2010) A gain-of-function mutation in TRPA1 causes familial episodic pain syndrome. Neuron 66: 671–680.
[33]
Viswanath V, Story GM, Peier AM, Petrus MJ, Lee VM, et al. (2003) Opposite thermosensor in fruitfly and mouse. Nature 423: 822–823.
[34]
Karashima Y, Talavera K, Everaerts W, Janssens A, Kwan KY, et al. (2009) TRPA1 acts as a cold sensor in vitro and in vivo. Proc Natl Acad Sci U S A 106: 1273–1278.
[35]
Dietzl G, Chen D, Schnorrer F, Su KC, Barinova Y, et al. (2007) A genome-wide transgenic RNAi library for conditional gene inactivation in Drosophila. Nature 448: 151–156.
