Fig. 2. (A,B) Effect of (A) cycloheximide (CHx) and (B) actinomycin D (ActD) on the activity of NMDA. Cells were incubated with the concentrations of actinomycin D or CHx indicated for 30 minutes before the addition of NMDA. The mRNA was then extracted 24 hours later and subjected to RT-PCR (using random hexamers) and quantitative PCR. The results are the mean ± s.e.m. of five experiments performed in triplicate. *P<0.001 and ^#P<0.001, significant difference from control values. (C) The half-life of ₂ mRNA was assessed in control and NMDA-treated cells by using actinomycin D (10 µg/ml). RNA was harvested at selected time points and the relative abundance of ₂ mRNA was determined by quantitative RT-PCR. The results are the mean ± s.e.m. of four experiments performed in triplicate.