Figure 3

Morphine effect on the expression of the opioid propeptides. Zebrafish embryos were exposed to 10 nmol/L morphine, and penk a, penk b and pomc a expression was established at 24 and 48 hpf and compared with controls. Embryos are oriented anterior toward the left and posterior toward the right. A total of 25 embryos were used for each treatment and for each time point, and the experiment was repeated three times.