Neurites grow with different outgrowth velocities.

Neurons were dissected from rat cortical brain, incubated for 16h to allow initial growth, and followed by image acquisition every 6h up to 70h after plating. (A-B) The growth dynamics of two example neurons, one with a low (A) and one with a high (B) outgrowth velocity, are shown over given time-period. (C) At each timepoint we quantified the length of the longest neurite of each neuron. Histograms show the length distribution of all longest neurites at the indicated timepoints. (D) At each timepoint we identified the top and bottom 10% and 25% quantile length as well as the median length. Exponential interpolation of the lengths for each selected quantile documented outgrowth velocities ranging from 0 to ~20 μm/h.