Effects of MPEP or CPCCOEt treatment on granule (A) and Purkinje (B) cell number in cerebellar cultures. Drugs were applied to the cultures as described in Figure 1. Cells were counted in four random fields per dish. Values are means ± SEM of four individual culture dishes. *p < 0.05 (one-way ANOVA + Fisher's PLSD) versus control values. Similar data were obtained in three experiments on different culture preparations.