Fig. 7. Stimulation and inhibition of growth cone PI3K activity by IGF-1 and by LY/Wm, respectively. GCPs, in the presence or absence of 20 µM LY or 100 nM Wm, were pre-incubated for 5 minutes at 37°C with or without IGF-1 (4 nM). PI3K was immunoprecipitated and subjected to kinase assay, using PI as a substrate. PI3P was isolated by TLC and phosphorylation assessed by storage phosphor imaging. LY reduced control levels and inhibited IGF-1-stimulation of PI3K activity. Wm reduced IGF-1-stimulated kinase activity to below control levels.