Dopamine receptor agonists affect the histaminergic and dopaminergic neuron numbers in 5-dpf fish brains. The cell numbers were quantified following histamine and TH1 co-immunostaining. A–C, no treatment. D–F, 10 mm
l-DOPA treatment. G–I, 7.5 μm quinpirole treatment. J–L, 10 μm SKF38393. Quantification of TH1-ir cell numbers after dopamine receptor agonist and antagonist administration is shown in PVOp (TH1 group 10, M) and in the diencephalic complex (TH1 group 13, N). Quantification of His-ir cell numbers is shown in O. Quantification of his-ir cell numbers in th2 MO1 + 2 morphant brains after drug treatments is shown in P. TH1 group numbers 10 and 13 are based on Ref. 61), corresponding to DC7 and DC6 in Ref. 36. His-ir positive cells are shown in green. TH1-labeled cells are shown in red. The number of brains analyzed and the mean value of the cell number are shown in the columns. *, p < 0.05; **, p < 0.01; ***, p < 0.001; one-way ANOVA with Tukey's test. Scale bar = 100 μm.