Figure 1
![Figure 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1472-6882-13-261/MediaObjects/12906_2013_Article_2135_Fig1_HTML.jpg)
Effects of different NGF concentrations (5 – 100 ng/ml) on stimulation of neurite outgrowth using differentiating N2a cells as an in vitro model. The results shown represent the mean ± SD; n = 3. Means not sharing a common letter were significantly different at p < 0.05.