Figure 6.

Analysis of the regenerative neurite growth. Time-lapse video microscopy was used to analyze the neuritic growth velocity of control and axotomized sensory neurons. A, Phase-contrast photograph showing neurons from a sciatic nerve injury conditioned culture 3 h (a) and 24 h (b) after plating. Scale bar 20 μm. B, Neurite initiation was evaluated 7 h after plating and estimated as a neurite length longer than one cell diameter. The total number of neurons counted per well ranged in between 20 and 30; eight wells were analyzed per conditions. The percentage of neurons having initiated neurite growth was significantly greater after an axotomy. C, Growth velocity, estimated as the length of a neurite measured each hour for 24 h, is significantly faster in axotomized neurons compared with control neurons. ***p < 0.001, Student's t test.