Fig. 9

The D1 receptor antagonist SCH23390 partially reverses AS1-induced attraction to noxious stimuli. A Temperature choice assay (28.5 °C vs 37.5 °C) with SCH23390. Control fish and those treated with 5 or 10 μM SCH significantly preferred the 28.5 °C side of the arena, whereas fish treated with 5 μM AS1 alone or 5 μM SCH + 5 μM AS1 significantly preferred the 37.5 °C side. Interestingly, fish treated with 10 μM SCH + 5 μM AS1 exhibited no preference between the two sides of the arena, indicating an abolition of choice following D1 receptor blockade. N = 74 fish for the DMSO condition, 58 fish for 5 μM SCH, 43 fish for 10 μM SCH, 81 fish for 5 μM AS1, 52 fish for 5 μM SCH + 5 μM AS1, and 50 for 10 μM SCH + 5 μM AS1. B Velocity data for the experiment in A. While AS1 treatment still significantly reduces swimming velocity at 37.5 °C and increases velocity at 28.5 °C, treatment with progressively higher concentrations of SCH does significantly reduce this AS1-induced heightened velocity at 28.5 °C, and at 10 μM SCH (+ 5 μM AS1), there is no longer a significant difference in swimming velocity between the 28.5 and 37.5 °C zones. * denotes significant differences in swimming velocities between the 28.5 and 37.5 °C zones for the same group of fish, + denotes significant difference from the 0 μM AS1 37.5 °C swimming velocity, and # denotes significant difference from the 0 μM AS1 28.5 °C swimming velocity. C, D AITC aversion assay. SCH alone does not elicit changes in AITC avoidance, whereas concentrations of SCH 5 μM and above partially attenuate AS1-induced attraction to AITC. N = 44 fish for DMSO, 38 for 1 μM SCH, 34 for 5 μM SCH, 39 for 10 μM SCH, 37 for 20 μM SCH, 14 for 5 μM AS1, 43 for 1 μM SCH + 5 μM AS1, 33 for 5 μM SCH + 5 μM AS1, 41 for 10 μM SCH + 5 μM AS1, 41 for 20 μM SCH + 5 μM AS1. * represent the significant difference of experimental traces from the DMSO-treated control fish at each indicated time point. E Distance of each individual larva from the AITC stimulus at the final time point (840 s) for the experiment shown in C, D. * presented directly over columns represent the significant difference between the DMSO-only control condition, and between other columns when indicated by lines. F Phototaxis assay. While SCH alone does cause a significant decrease in the percentage of fish found in the light half of the arena when applied at higher concentrations, fish in these conditions still significantly prefer the light half of the arena. When co-applied with AS1, 15 μM and 20 μM SCH are able to significantly reduce AS1-induced preference for the dark, with 15 μM SCH abolishing preference entirely. N = 80 fish for DMSO, 80 for 10 μM SCH, 40 for 15 μM SCH, 80 for 20 μM SCH, 80 for 2.5 μM AS1, 40 for 10 μM SCH + 2.5 μM AS1, 40 for 15 μM SCH + 2.5 μM AS1, and 40 for 20 μM SCH + 2.5 μM AS1. G Temperature choice assay (28.5 °C vs 37.5 °C) with fish treated with 2.5 μM Analog 9089110 and/or 10 μM SCH23390. Control fish and those treated with 10 μM SCH significantly preferred the 28.5 °C side of the arena, whereas analog-treated fish significantly preferred the 37.5 °C side. As with AS1, treatment with 10 μM SCH23390 significantly attenuated analog-induced attraction to noxious heat, although these fish still preferred noxious heat over rearing temperature. N = 48 fish for the DMSO condition, 42 fish for 10 μM SCH, 55 fish for 2.5 μM Analog 9089110, and 60 fish for 2.5 μM Analog 9089110 + 10 μM SCH. H Velocity data for the experiment shown in G. * denotes significant differences in swimming velocities between the 28.5 and 37.5 °C zones for the same group of fish, + denotes significant difference from the 0 μM Analog 37.5 °C swimming velocity, and # denotes significant difference from the 0 μM Analog 28.5 °C swimming velocity. Similar to our AS1 experiments, treatment with 10 μM SCH was able to partially reverse the Analog-induced inversion of swimming velocity, at least in the 28.5 °C zone. */^#/⁺ p < 0.05, **/^##/⁺⁺ p < 0.01, ***/^###/⁺⁺⁺ p < 0.001. Two-way ANOVA with Tukey’s multiple comparisons test used in A–D, F–H. One-way ANOVA with Tukey’s multiple comparisons test used in E. For all temperature and light/dark choice experiments, a one-sample t test was performed with a hypothetical mean of 50% to determine if fish were significantly choosing one side of the arena over the other