Fig. 7. Time course of ketamine-induced activation of cell cycle proteins. (A ) Western blots of protein lysates from primary neurons exposed to ketamine (10 μm) for different incubation periods demonstrate a coordinated time-dependent increase in cell cycle–related proteins. (B ) Quantitation of the immunoblots confirm the significant increases in immunoreactive band densities (n = 4, *P < 0.05, compared with the control group). Data are presented as mean ± standard error. Bim = Bcl2-interacting mediator of cell death; cdk4 = cyclin-dependent kinase 4.