Fig. 4.

Effects of PI3K inhibition and melatonin receptor blockade on melatonin-induced CREB phosphorylation. Melatonin (10µM) was applied to primary cultures for 12 hr in the absence or presence of the inhibitor indicated. Left panel is the representative blot, and right panel shows quantitative verification. The phospho-CREB/CREB ratio was expressed as mean±SEM. CREB phosphorylation by melatonin was partially inhibited by pretreatment of the cells with wortmannin or luzindole. ^*p<0.05 indicates statistically significant difference from the melatonin treated group.