Behavioral Aversion to AITC Requires Both Painless and dTRPA1 in Drosophila

• Published in: Frontiers in neural circuits 2018-07, Vol.12, p.45-45
• Main Authors: Mandel, Samantha J, Shoaf, Madison L, Braco, Jason T, Silver, Wayne L, Johnson, Erik C
• Format: Article
• Language: English
• Subjects: Allyl isothiocyanate; Animals; Aversion; Behavior; Behavior, Animal - physiology; Calcium; Calcium - metabolism; Drosophila; Drosophila melanogaster - metabolism; Drosophila Proteins - metabolism; Food consumption; Food intake; Genotype & phenotype; Genotypes; Heat; Insects; Ion Channels - metabolism; Isothiocyanate; Isothiocyanates - metabolism; Males; Neurons; Neurons - metabolism; Neuropeptides; Neuroscience; nociception; Nociception - physiology; Oviposition; Pain perception; Peripheral populations; Phenotypes; Proboscis; Sucrose; TRPA; TRPA1 Cation Channel - metabolism; Variance analysis
• ISSN: 1662-5110; 1662-5110
• DOI: 10.3389/fncir.2018.00045

There has been disagreement over the functional roles of the gene product in the detection and subsequent behavioral aversion to the active ingredient in wasabi, allyl isothiocyanate (AITC). Originally, was reported to eliminate the behavioral aversion to AITC, although subsequent reports suggested that another trpA homolog, , was responsible for AITC aversion. We re-evaluated the role of the gene in the detection of AITC, employing several different behavioral assays. Using the proboscis extension reflex (PER) assay, we observed that AITC did not reduce PER frequencies in or mutants but did in wild-type genotypes. Quantification of food intake showed a significant decline in food consumption in the presence of AITC in wild-type, but not mutants. We adapted an oviposition choice assay and found wild-type oviposit on substrates lacking AITC, in contrast to and mutants. Lastly, tracking individual flies relative to a point source of AITC, showed a consistent clustering of wild-type animals away from the point source, which was absent in mutants. We evaluated expression patterns of both and , which showed expression in distinct central and peripheral populations. We identified the transmitter phenotypes of subsets of and neurons and found similar neuropeptides as those expressed by mammalian trpA expressing neurons. Using a calcium reporter, we observed AITC-evoked responses in both and expressing neurons. Collectively, these results reaffirm the necessity of in nociceptive behaviors and suggest experiments to further resolve the molecular basis of aversion.