Figure 2.

Effect of opioid treatment on ERK and PEBP phosphorylation in SH-SY5Y cells. (A) Cells were treated with 1 μM morphine for the indicated time intervals. (B) Cells were exposed to 1 μM DAMGO for the indicated time intervals. Data are presented as the mean ± standard error of the mean from three independent experiments. One-way analysis of variance was used followed by Dunnett’s post hoc test. ^*P<0.05 and ^***P<0.001, compared with the con. PEBP, phosphatidylethanolamine-binding protein; DAMGO, (D-Ala², MePhe⁴, Gly⁵-ol) enkephalin; ERK, extracellular signal-regulated kinase; CHO cells, Chinese hamster ovary cells; con, control.