Fig. 2

MOP (a) and NOP (b) relative gene expression in SH-SY5Y neuroblastoma cells following 5 h of exposure to 10 μM morphine, 100 μM naloxone and their association. Data represent 2^−DDCt values calculated by using the DDCt method. Gene expression was normalized to GAPDH as housekeeping gene. Data are expressed as mean ± SEM (° p = 0.074; ** p < 0.01, *** p < 0.001 vs vehicle; ## p < 0.01 and ### p < 0.001 vs naloxone + morphine; data analyzed by one-way ANOVA followed by Newman-Keuls tests)