BMP-5 is less potent than BMP-7 but equally efficacious in promoting dendritic growth in cultured sympathetic neurons. Beginning on the fifth day in vitro after elimination of glial cells, SCG neurons were exposed to varying concentrations of BMP-5 or BMP-7. After 6 days of exposure to BMPs, cultures were immunostained with a mAb to the dendritic marker MAP2. Dendritic growth was quantified with respect to the percent of cells with dendrites (A), number of dendrites per neuron (B) and total dendritic length (C). Data in panels B and C are presented as the mean ± S.E.M. (n = 60 per experimental condition). * p < 0.05.