Effects of forskolin on the mESC frequency in line 34 larvae. The concentration-dependent increase of mESC frequency is shown in the ordinate as the difference of mESC events per minute between the average of frequency during a 5 min interval shortly after application of forskolin and that of a 5 min interval between 25 and 30 min after drug application. Data from three cells for 50 μm, from three cells for 100 μm, from six cells for 200 μm, from three cells for 300 μm, from six cells for 400 μm, and from four cells for 500 μm were averaged. Error bars indicate SEM.