Figure 1.

Morphine, but not fentanyl, decreases NeuroD activity. Primary rat hippocampal cultures were treated with PBS (control), 1 μm morphine, or 10 nm fentanyl for 3 d. A, The amount of phosphorylated serine was determined in immunoprecipitated NeuroD to indicate NeuroD phosphorylation (pND). Total NeuroD (ND) was measured in the nuclear extracts. The total CaMKIIα (CaM), phosphorylated CaMKIIα (pCaM), total ERK, and β-actin were detected in whole-cell lysis. Total ERK and β-actin served as internal controls. IP, Immunoprecipitation; IB, immunoblotting. B, The levels of miR-190 and NeuroD mRNA were measured by real-time PCR. C, mRNA levels of DCX, ND4, Notch1, and Robo1 were determined by real-time PCR. A–C, Results were normalized against those in control samples. Error bars indicate SD. *p < 0.05.