(A) Representative Western blots of total tau (HT7), and phosphorylated tau at residues S202/T205 (AT8), T231/T235 (AT180), T181 (AT270) and S396/S404 (PHF-1) in primary cortical neuronal cells for Control and zileuton treatment. (B) Densitometric analyses of the immunoreactivities to the antibodies shown in the previous panel (*p < 0.01). (C) Representative Western blot analyses for cyclin-dependent kinase (cdk)-5, p35, p25, GSK3α, GSK3α, p-GSK3α and p-GSK3β. (D) Densitometric analyses of the immunoreactivities to the antibodies shown in the previous panel (*p < 0.01;**p<0.001). Values represent mean ± sem (n= 4 per condition).