Effect of TrkA receptor antagonist on Riv-mediated enhancement of NGF-induced neurite outgrowth in PC12 cells.

PC12 cells were pre-incubated in the presence or absence of GW-441756 (1 μM) for 4 h. NGF and Riv were added, and cells were incubated for an additional 24 h before neurite outgrowth assays. For each condition, values are reported as the mean ± SD for all PC12 cells included within five randomly chosen fields. **p ††p < 0.01 compared with NGF+Riv).