(A) SH-SY5Y cells were pretreated with or without 20 mM lithium chloride for 1 h followed by treatment with 4 µg/ml tunicamycin for 3 or 4 h. Cell lysates were immunoblotted for CHOP and β-actin. (B) SH-SY5Y cells were pretreated for 1 h with the GSK3 inhibitors 5 µM kenpaullone (Kp), 5 µM 6-bromoindirubin-3'-oxime (BIO), or 5 µM CHIR99021 (CHIR), followed by treatment with 4 µg/ml tunicamycin for 4 h and immunoblotting for CHOP and β-actin. Quantitative values are means ± SEM, n=3, *p< 0.05 compared with no GSK3 inhibitor.