Figure 1. Neurons required during odor conditioning for aversive olfactory learning.

(A) Schematic of aversive olfactory learning assay. Adult worms are washed off food and conditioned with odor in buffer for 90 min, then washed again before being tested in a butanone chemotaxis assay for 1–2 hr. (B) Partial C. elegans wiring diagram showing neurons tested for effects on aversive learning and their synaptic connections with AWC and each other. (C) Aversive learning in animals expressing the histamine-gated chloride channel (HisCl1) under cell-specific promoters, assayed with or without 10 mM histamine in the conditioning medium. Chemotaxis assays (1:1000 butanone dilution) were performed on histamine-free plates. Error bars represent S.E.M. P values were generated by 2-way ANOVA for interaction of odor condition and presence of histamine (**p<0.001, *p<0.05). n = 3–61 assays, 50–200 animals/assay. (D) Aversive learning in animals carrying the gcy-28d::HisCl transgene and a second transgene expressing dsRNA that targets HisCl. Tested as in (B). Error bars represent S.E.M. P values were generated by 2-way ANOVA for interaction of odor condition and presence of histamine (**p<0.001, *p<0.05, n.s. not significant). n = 9–15 assays, 50–200 animals/assay. (E) Aversive learning in animals expressing the gain-of-function potassium channel UNC-103 under the gcy-28d promoter. P values were generated by 2-way ANOVA for interaction of genotype and condition (**p<0.001). n = 8 assays, 50–200 animals/assay. (F) Appetitive learning in wild-type and gcy-28d::unc-103(gf) animals after conditioning with butanone and food (1:10 butanone dilution). 2-way ANOVA for interaction of genotype and condition (n.s. not significant). n = 8 assays per condition, 50–200 animals/assay.

DOI: http://dx.doi.org/10.7554/eLife.14000.003