Fig. 4. NT-induced morphological differentiation and neurite outgrowth in SH-SY5Y/wt, SH-SY5Y/trkC, and SH-SY5Y/trkA cells. A, phase-contrast micrographs of SH-SY5Y/trkC cells grown in the presence of NT-3 and/or NGF. Cells were grown for 10 days in serum-containing medium alone (a), in serum-containing medium supplemented with 100 ng/ml NT-3 (b), 100 ng/ml NGF (c), or 100 ng/ml NT-3 + 100 ng/ml NGF (d). Bar in a, 25 µm. B, percentage of cells with long neurites in SH-SY5Y/wt cells. Cells were grown for 8 days in serum-containing medium alone or with supplementation of 100 ng/ml NT-3, 100 ng/ml NGF, or 100 ng/ml NT-3 + 100 ng/ml NGF. C, SH-SY5Y/trkC cells (clones 3:1 and 3:2) treated as in B, supplemented with 100 ng/ml NT-3 or 100 ng/ml NGF and analyzed as in B. D, SH-SY5Y/trkA cells treated and analyzed as in C.