Fig. 8. Northern blot analysis of the expression of immediate-early genes in NT-3-stimulated SH-SY5Y/trkC and NGF-stimulated SH-SY5Y/trkA cells. A, SH-SY5Y/trkC (clone 3:1) and SH-SY5Y/trkA cells, grown in serum-containing medium, were stimulated with 100 ng/ml of NT-3 and NGF, respectively, for the indicated time periods. Total RNA (15 µg) was analyzed for expression of c-jun (2.7 and 3.2 kb), c-fos (2.2 kb), and NGFI-A (3.0 kb). B, SH-SY5Y/trkC (clones 3:1 and 3:2) and SH-SY5Y/trkA cells, grown in serum-containing medium, were stimulated for 60 min with increasing concentrations of NT-3 or NGF. Total RNA (15 µg) was analyzed for expression of c-fos (2.2 kb) and NGFI-A (3.0 kb). In both panels, GAPDH (1.5 kb) mRNA levels were used as a reference for the amount of loaded RNA.