Figure 8.

Ligand-activated GFRα2b antagonizes the neurite outgrowth induced by retinoic acid (RA). RA (5 μm) induced neurite outgrowth in GFRα2b-expressing Neuro2A cells. When treated together with GDNF or NTN (50 ng/ml), neurite outgrowth induced by RA was significantly attenuated. A, Phase-contrast images of Neuro2A cells stably expressing GFRα2b, treated with RA, GDNF, or NTN for 3 d. B, Graph of the percentage of cells bearing neurite with at least two times the length of the cell bodies and the effects of RA, GDNF, and NTN. Similar results were obtained from three independent clones. Significant differences in the percentage of cells bearing neurites between ligand stimulated and control were calculated using the paired Student's t test (*p < 0.002). Error bars indicate mean ± SD of triplicate measurements.