FIGURE 3.

Regulation of SRF-mediated transcription and dendritic morphology by activin. Follistatin (250 ng/ml) was added to the medium 30 min before activin (100 ng/ml) stimulation. A, activation of SRF-mediated transcription by activin and its inhibition by follistatin. The reporter vectors were transfected into cortical neurons. Twenty-four hours later, the cells were stimulated without (control) or with activin (100 ng/ml) for 24 h. Bar graphs represent the mean ± S.D. from four samples. The same trends were obtained from at least two independent experiments. ***, p < 0.001; #, p < 0.05; N.S., not significant, p > 0.05. B, activin-induced dendritic complexity and its inhibition by follistatin. C and D, dendritic complexity analyzed in the experimental conditions shown in B. Graphs represent the mean ± S.D. from four independent experiments. C, Sholl analysis. Supplemental Table 1 shows the statistical significance. D, dendritic length. ***, p < 0.001; ##, p < 0.01; N.S., p > 0.05.