IGF-1 enhances neurite-outgrowth.

(A) E14 neurospheres were allowed to differentiate in the presence or absence of IGF-1. (B, C) Analysis of average of primary and secondary neurite length and average number of neurites per cell in NSCs differentiated in presence and absence of IGF-1. Neurite length was measured in randomly chosen cells (at least 8–10 different fields and approx 5 cells per field) by tracing individual neurites (as described in experimental procedures) and results are expressed as (B) average of total primary and secondary neurite lengths or (C) average number of neurites per cell. Statistical significance of the difference was determined using ANOVA. The result shows the mean ± S.E. of n = 3 combined experiments (***p<0.001, *p<0.05).