Figure 1.

Effects of BMP-7 and PD98059 on the morphology of sympathetic neurons. Phase-contrast (A, C, E, G) and fluorescence (B, D, F, H–J) micrographs of neurons immunostained with an mAb to MAP2. Neurons in control cultures had only axons (A, B). Neurons exposed to BMP-7 (10 ng/ml) for 5 d extended dendrites (C, D), and this response was enhanced by treatment with PD 98059 (10 μm; E, F). PD 98059 alone had no effect on dendritic growth (G, H). I and J are low-power micrographs of cells exposed to BMP alone (I) or in the presence of PD 98059 (J). Scale bars, 25 μm.