The SH-SY5Y cells were pretreated with morphine (10 μM) exposure for 48 h, precipitated with naloxone (10 μM) for 15 min, and then the levels of cAMP were measured. The data are from the analysis of the ratio of the levels of cAMP relative to the control (Sal+Sal), and are presented as the mean ± S.D. of three separate experiments. ##P < 0.01, compared with the Sal + Sal group; **P < 0.01, compared with the Mor + Sal group.
Wen et al. BMC Neuroscience 2012 13:63 doi:10.1186/1471-2202-13-63