Fig. 7

Effect of the endocannabinoid receptor antagonists AM251 and AM630 on development and inflation of 5 dpf larval zebrafish swim bladders. (A) AM251 and AM630 treatments at the early stage either from 0 to 24 hpf or 24 to 48 hpf showed fully inflated to partial or non-inflated swim bladder (SB; red arrow) development in zebrafish larvae observed at 5 dpf. Representative images of three different fish, labelled 1, 2 and 3, show fully inflated, partially inflated or non-inflated swim bladders in larvae. (B–G) Rates of swim bladder inflation at 0–24 hpf (B–D: n=73, 59, 57 and 58 for vehicle control, 0.5 µmol l⁻¹ AM251, 5 µmol l⁻¹ AM630 and 0.5 µmol l⁻¹AM251+5 µmol l⁻¹ AM630 treatments, respectively) and at 24–48 hpf (E–G: n=78, 58, 61 and 60 for vehicle control, 0.5 µmol l⁻¹ AM251, 5 µmol l⁻¹ AM630 and 0.5 µmol l⁻¹ AM251+5 µmol l⁻¹AM630 treatments, respectively). Data are presented as means±s.e.m. ^aSignificantly different from vehicle control, P<0.05; ^bsignificantly different from 0.5 µmol l⁻¹ AM251, P<0.05; ^csignificantly different from 5 µmol l⁻¹ AM630, P<0.05 (one-way ANOVA followed by Tukey’s post hoc multiple comparisons test).