Figure 2.

Drosophila larvae exhibit nocifensive rolling in response to menthol. (a) Menthol-evoked rolling. Top, cartoon. Bottom, video stills. (b) Cumulative proportion of wild-type rollers in response to menthol. The rolling response increased at higher menthol concentrations (% w/v). Cumulative proportion ± s.e.p. n = 30 for each condition. (c) Proportion of rollers in response to 8% menthol. Compared to wild-type, fewer TrpA1 and Trpm mutants rolled in response to menthol (TrpA1^W903*, p = 0.0221; TrpA1¹, p = 0.0479; Trpm², p = 0.0221; Trpm²/Trpm df, p = 0.0221). Trpm and TrpA1 are haplosufficient for menthol sensitivity, but fewer transheterozygous mutants rolled in response to menthol (p = 0.0090). Proportions represented as % rollers ± s.e.p. n = 30 for each condition. (d) Latency to roll in response to 8% menthol. painless mutation sensitized rollers (p = 0.0006), while TrpA1^W903* mutation desensitized rollers (p = 0.0388). Latency represented as time to roll in seconds ± s.e.m. n proportional to % rollers, where initial sample size was 30. (Online version in colour.)